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Travel Time Modelling Using Time Series of Nitrate Concentration in Groundwater Impro...
Baibaswata Bhaduri
Muddu Sekhar

Baibaswata Bhaduri

and 3 more

September 25, 2021
Rivers can act as mirrors to in-catchment processes, but integrated concentration-discharge dynamics might not be sufficient for constructing a well-posed solute travel time determination problem. One remedy is to look inside the catchment and see if the extra information provided by long-term time series of groundwater solutes constrains the problem or provides us with some additional insight on retrieving the processes which the stream is aggregating. To test this notion, we used data for Kerrien, a well-studied agriculture dominated small headwater catchment of the French Critical Zone Observatory in Brittany. It contains long-term nitrate concentration time-series from a network of piezometers as well as a stream outlet. In this study, a parsimonious, conceptual dual-permeability mixing model already developed for streams was adapted for piezometers along with detailed uncertainty and sensitivity analysis. We found out the nitrate flushing times of mid to upslope piezometers were consistently higher than the stream outlet. We further observed an asynchronicity in seasonal concentration-discharge dynamics between the piezometers and the stream. We hypothesize the reason behind this counterintuitive finding to be extensive riparian denitrification, vertical stratification of groundwater and disconnect between the stream and the deeper flowpaths that carry legacy contamination, evidenced by the non-closure of water budget at the stream outlet. As a consequence, we argue that in headwater catchments the stream signature might not fully reflect internal processes which can be revealed only by using piezometer data. This adapted conceptual framework could be of great interest for semi-arid catchments where groundwater monitoring could be used in combination or as an alternate to ephemeral streams in travel time determination.
Uniformity in bioprosthetic mitral valve sizing -- when will we get there?
Cian Tan
Professor Mohamad Bashir

Cian Tan

and 2 more

September 25, 2021
Much has changed since the introduction of surgical valve repair in the 1950s, from the introduction bioprosthetic valves to percutaneous approaches to valve repair. Yet, despite substantial advancements in bioprosthetic valve technology, there has been a lack of direct, independent comparison between bioprosthetic mitral valve devices, accompanied by a marked heterogeneity in approaches to the sizing and selection thereof. Wang et al. have hence endeavoured to evaluate, head-to-head, the technical successes and biomechanical outcomes associated with three different bioprosthetic mitral valves (Epic, Abbott, IL; Mosaic, Medtronic, MN; Mitris Resilia, Edwards Lifesciences, CA) in a porcine model, under standardised haemodynamic and anatomical conditions. With a robust experimental technique, they have made clear the heterogeneity in both sizing and biomechanical properties between bioprosthetic mitral valves, and have further emphasised the need for a uniform approach to the manufacturing and sizing of bioprosthetic valves.
Reversible blindness after erroneous prescription of closantel: A case report
Hamed Cheraghmakani
Reza Jafari

Hamed Cheraghmakani

and 3 more

September 25, 2021
A 20-year-old girl referred with vision loss upon closantel use. Plasma exchange and high-dose corticosteroid pulse therapy were administered. A 2.5-year follow-up showed improved vision and increased layer thickness of the peripheral nerve fiber. Early treatment with plasma exchange and high-dose corticosteroid therapy can be beneficial to reverse closantel toxicity.
Survival of pediatric Hodgkin lymphoma patients treated with doxorubicin, bleomycin,...
Sebastian de Armas
Carolina Huertas-Ayala

Sebastian de Armas

and 7 more

September 25, 2021
Background: ABVD, the standard-of-care in adult Hodgkin lymphoma (HL), has not been directly compared to ABVE-PC, a pediatric regimen designed to reduce late-effects. We aimed to compare the effectiveness and associated toxicities of these two regimens used in the same institution. Methods: This retrospective cohort study evaluated a total of 224 patients diagnosed with HL between 1999 and 2018 at Children’s Hospital Los Angeles (CHLA), of which 93 patients were eligible having received ABVD (n=46) or ABVE-PC (n=47) chemotherapy as their initial treatment. Descriptive analyses were performed using the Student’s t-test or Fisher’s exact test. Survival analysis used the Kaplan-Meier method. Events included: death, relapse, secondary malignancy, need for radiation therapy, pulmonary toxicity and cardiomyopathy determined by shortening fraction <29%. Analyses followed an intention-to-treat principle. Results: There was no difference in baseline characteristics between the patients receiving ABVE-PC or ABVD in regard for stage, risk group or prognostic variables, such as the presence or absence of “B” symptoms, bulky disease, and extra-nodal involvement. A greater proportion of patients treated with ABVE-PC received consolidating external beam radiation treatment (XRT) either by randomization or by response compared to ABVD (59.6% vs 32.6% respectively, p=0.01). While not statistically significant, response to therapy, assessed by PET/CT where available, mirrored the need for radiation (rapid response 58.3% vs 90.0%, n=34, p=0.11). There was no difference in event-free survival (p=0.63) or overall survival (p=0.37) with a median follow up length of 3.9 years. Conclusion: ABVD and ABVE-PC achieved similar survival outcomes in our single-institution cohort
SIROLIMUS EFFICACY IN THE TREATMENT OF CRITICALLY- ILL INFANTS WITH CHYLOUS EFFUSIONS
sxagarw4@texaschildrens.org
Berkley  Anderson

Shreya Agarwal

and 5 more

September 25, 2021
Background: While rare in children, chylothorax is a significant cause of respiratory morbidity and can lead to malnutrition and immunodeficiency. Historically, the traditional pharmacological treatment has been octreotide. There are several treatments that have been utilized in the past few years including sirolimus, however data regarding their efficacy and outcomes is limited. Furthermore, sirolimus has proven efficacy in complex vascular malformations, and hence, its utility/efficacy in pediatric chylous effusions warrants further investigation. Methods: In this retrospective study at Texas Children’s Hospital, data were extracted for all patients with chylothorax who were treated with sirolimus between 2009 and 2020. Details regarding underlying diagnosis, co-morbidities and number of days from sirolimus initiation to resolution of effusion were collected. Descriptive statistics were used to analyze the study cohort. Results: Initially a total of twelve infants were identified. Among them, seven patients had complete data and were included in the study. The mean duration of sirolimus treatment needed for chest tube removal was 16 days, with a median of 19 days and range of 7- 22 days. Chest tube output corresponded with sirolimus serum trough levels and trended down prior to chest tube removal. Conclusion: With close monitoring, sirolimus is a safe and effective therapy for pediatric lymphatic effusions even in critically-ill infants. The study also demonstrates shorter duration of chest tube requirement after initiation of sirolimus compared to previous studies. Our conclusion is based on a small case series due to the rare incidence of the condition.
Reactogenicity of influenza vaccination in children with cancer and hematologic disea...
Almudena Laris-González
Martha Aviles-Robles

Almudena Laris-González

and 3 more

September 25, 2021
LETTER TO THE EDITOR
“Giving the gift of life twice”: Understanding the lived experiences of parent donors...
Megan Schaefer
Vanessa Aguilera

Megan Schaefer

and 5 more

September 25, 2021
Background: The use of parental donors in pediatric haploidentical hematopoietic cell transplantation is increasing, but research on the psychosocial impact of parental donation is currently limited. We conducted a retrospective, qualitative study to explore parental perceptions of the donation process and the impact of being a donor (or non-donor) on parents’ adjustment and coping with their child’s transplant experience. Methods: Parents/caregivers of children who underwent transplantation with a parental donor or a matched unrelated donor (N = 136) participated in interviews and completed an open-ended questionnaire. Both bereaved parents and parents of survivors were surveyed. Results: Six themes were identified in the data: level of understanding and satisfaction; perception of choice; preparation for donation; perceptions of donation and infusion; benefit-finding; and psychological impact of transplantation. Most parents were satisfied with the information they received and reported a good understanding of transplantation and donation procedures. Parents were divided on perspectives of choice, but their responses reflect that the necessity of saving their child’s life does not allow for choice. They described considerable effort to prepare for transplantation, physically, emotionally, and logistically. Parents acknowledged the psychological impact while identifying positive outcomes that resulted from their child’s transplant journey. Conclusions: Results highlight the unique experiences of parental donors and non-donors from the anticipation phase to the completion of their child’s transplant. Additionally, findings inform supportive care guidance by highlighting the need to assess parental donors’ emotional functioning, provide support post-donation, and conduct bereavement follow-up.
Recommended Scoring Approach for the Pediatric Patient-Reported Outcomes version of t...
Pamela Hinds
Laura Pinheiro

Pamela Hinds

and 9 more

September 25, 2021
Background Collecting symptom, function and adverse event (AE) data directly from children and adolescents undergoing cancer care is more comprehensive and accurate than relying solely on their caregivers or clinicians for their interpretations. We developed the Pediatric Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (Ped-PRO-CTCAE) measurement system with input from children, parents, and clinicians. Here we report how we determined the recommended Ped-PRO-CTCAE item scoring approach. Methods Scoring approaches compared were 1) at the AE attribute (frequency, severity, interference) using ordinal and dichotomous measures, 2) a weighted composite AE item score by AE attribute (0.5 - frequency; 1.0 - severity; 1.5 - interference), and 3) overall number of AEs endorsed. Associations of each AE attribute, AE item score and overall AE score with the PROMIS® Pediatric measures of anxiety, depressive symptoms, and fatigue were examined. The ability of the overall Ped-Pro-CTCAE AE score to identify patients with PROMIS symptom T-scores worse than reference population scores was assessed. Clinician preference for score information display was elicited through interviews. Results The diverse scoring approaches yielded similar outcomes, including positive correlations of the Ped-PRO-CTCAE attributes, AE item score, and the overall AEs score with the PROMIS Pediatric measures. Clinicians preferred the most granular display of scoring information (actual score reported by the child and corresponding descriptive term). Conclusions Although three scoring approaches yielded similar results, we recommend the AE attribute level of one score per Ped-Pro-CTCAE AE attribute for its simplicity of use in clinical care and research.
”Comment on: [Pediatric oncology infrastructure and workforce training needs: A repor...
Julietta Simonyan
Lusine  Hakobyan

Julietta Simonyan

and 10 more

September 25, 2021
Comment on: [Pediatric oncology infrastructure and workforce training needs: A report from the Pediatric Oncology East and Mediterranean (POEM) Group]Julietta Simonyan1, Lusine Hakobyan1,2, Medea Anastasiadi1,2, Lilit Sargsyan1,2, Lala Vagharshakyan1,2, Ruzanna Papyan1,2, Lusine Krmoyan1,2, Mihran Martirosyan1, Samvel Danielyan3, Armen Muradyan1, Gevorg Tamamyan1,21 Yerevan State Medical University, Yerevan, Armenia2 Pediatric Cancer and Blood Disorders Center of Armenia, Hematology Center after Prof. R.H. Yeolyan, Yerevan, Armenia3 Hematology Center after Prof. R.H. Yeolyan, Yerevan, Armenia Corresponding Author: Simonyan Julietta, MD, Yerevan State Medical University, Koryun 2, AM0025, Yerevan, Armenia, Phone: +37499492660, Email: simonyanjulietta@gmail.com Main text word count: 546 References: 1 A short running title: First pediatric hematology-oncology fellowship program in Armenia Keywords: pediatric hematology-oncology, fellowship, Armenia In the recent PBC paper by Khan and colleagues1, the pediatric oncology workforce training needs for the East and Mediterranean region were examined and reported. Armenia, as a part of the Pediatric Oncology East and Mediterranean (POEM) Group, was among the study participants and respondents. At the time of the survey in 2018, Armenia didn’t have a pediatric hematology/oncology training program, which was accordingly reported. In this letter, we describe the recent developments in that regard and the establishment of the first pediatric hematology/oncology fellowship program in our country. On September 4, 2014, the Government of the Republic of Armenia (RA) approved a list of narrow medical specialties of the RA, where one unified specialty - pediatric hematology/oncology was mentioned for the first time. Before that, two separate specializations were existing – pediatric hematology and pediatric oncology, and to obtain those qualifications, it was necessary, after the completion of MD program at the medical university (6 or 7 years), to continue either with an oncology residency program (2 years, which later became 3 years), or hematology program (3 years). Both curricula included pediatric and adult programs, accordingly, the fellows were practicing both pediatric and adult medicine. Before 1998 at the Yerevan State Medical University (YSMU), a faculty of Pediatrics existed with a pediatric-only MD program, however, it was closed in 1998. To become a pediatric hematologist or pediatric oncologist, after the pediatric MD program, graduates were entering into hematology or oncology training, focusing on the pediatric part. Taking into account the successful programs implemented into pediatric hematology/oncology in our country, as well as the dedication and willingness of the local specialists and the need for new specialists, on June 26, 2019, the Board of Trustees of YSMU decided to establish the Department of Pediatric Oncology and Hematology, with a “pediatric hematologist-oncologist” fellowship program and on July 1, 2019, by the decree of the Rector of YSMU, the Department was established. The fellowship program has been adapted based on the educational programs of St. Jude Children’s Research Hospital, Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, and the American Board of Pediatrics programs. In the first year, five clinical fellows entered the program, and two hematology fellows of the 2nd and 3rd year, respectively, transferred to our program. During the second year, three more fellows successfully joined the program, so the number of pediatric hematology – oncology fellows became 10. Besides clinical skills and knowledge, special attention was dedicated to the research component of the program, and a mandatory requirement of conducting research and publication of at least one peer-reviewed article in an international reputable journal was introduced for the completion of the fellowship program. Another mandatory requirement for fellows is the knowledge of at least two foreign languages (mostly English and Russian). These two requirements were introduced for the first time in Armenia. It is worth to mention, that within 2 years since its establishment, pediatric hematology and oncology fellowship program became one of the successful programs at the medical university. Although, at the beginning we were thinking that high requirements might add additional difficulties to attract young physicians to join this emotionally and professionally difficult profession, but it was just the opposite: some of the best graduates with the highest performance chose pediatric hematology-oncology and joined the program․References1. Khan MS, Al-Jadiry MF, Tarek N, et al. Pediatric oncology infrastructure and workforce training needs: A report from the Pediatric Oncology East and Mediterranean (POEM) Group. Pediatr Blood Cancer. 2021;68(9). doi:10.1002/PBC.29190
Psychosocial function of Dutch children with cancer and their caregivers during diffe...
Marloes van Gorp
Heleen Maurice-Stam

Marloes van Gorp

and 8 more

September 25, 2021
We compared psychosocial functioning of children with cancer and their caregivers in several phases of the COVID-19 pandemic to before COVID-19. One or more questionnaires on health-related quality of life (HRQoL) or fatigue of children or distress of their caregivers was available from 1644 families. In children with cancer, HRQoL was stable throughout the COVID-19 pandemic. Fatigue was slightly lower and sleep somewhat better during the pandemic than before. Caregiver distress was lower in the first pandemic phase, but increased to pre-COVID-19 levels in later phases, indicating that the length and consequences of the pandemic may be weighing on them.
SARS-CoV-2 precipitated Kasabach-Merritt syndrome in a child with Kaposiform Hemangie...
Vanessa Zarate
Alejandra Cahuata

Vanessa Zarate

and 5 more

September 25, 2021
Kaposiform hemangiendothelioma usually occurs in children under two years of age and develops thrombocytopenia secondary to sequestration of platelets within (Kasabach-Merritt phenomenon) and is complicated by secondary consumption of fibrinogen and clotting factors. SARS-CoV-2 produces cutaneous endothelitis as a direct effect of the presence of the virus and the host inflammatory response. We describe an 8-month-old boy with leukemia and SARS-CoV-2 infection who developed Kasabach-Merritt phenomenon, coagulopathy, and intestinal involvement. Given the emerging evidence of endothelial and vascular involvement in COVID-19, the development of tests to detect vascular injury may be critical to guide the use of new therapeutic strategies.
COVID-19 vaccination in pediatric cancer patients: a high priority
Yashika Charla
Manas Kalra

Yashika Charla

and 3 more

September 25, 2021
A document by Yashika Charla. Click on the document to view its contents.
Diagnosis and management of neutropenia in children: consensus audit of the “Associaz...
Francesca Fioredda
Daniela Onofrillo

Francesca Fioredda

and 14 more

September 25, 2021
SUMMARY Neutropenia is a generic term that indicates a reduction of neutrophils below the threshold for age and race. This condition encompasses a number of diseases with a wide range of duration and severity. In the present paper, the approach to diagnosis and treatment of neutropenia has been reviewed and implemented with the knowledge acquired during the last decade, by a group of experts, 10 years after the first publication. The diagnostic itinerary highlights the most important tools available to define the type of neutropenia and updates the list of genes causative of the disease. In addition, the present paper underlines the progresses towards a better definition of “primary autoimmune neutropenia” without remission which often hides different diseases. Moreover, indications on how to speed up neutropenia diagnosis and the indications to perform the bone marrow examination in the genetic forms, are given. The management and treatment of the “well-known” diseases and “special situations” are also reviewed giving literature derived and expert opinion-based suggestions tailored on the single patient/diagnosis.
Twice Neglected? Neglected Diseases in Neglected Populations
Ethel Weld
Catriona Waitt

Ethel Weld

and 3 more

September 25, 2021
It is unfortunately true that clinicians lack the necessary evidence to know how to use medications properly in large sections of the population, and we do not have optimal drugs to use in many Neglected Tropical Diseases (NTDs). NTD’s often disproportionately affect neglected populations such as children and pregnant women. As reliable access to safe, effective preventives and treatments can break the cycle of poverty, illness, and ensuing debility that further perpetuates poverty, it is of paramount importance to investigate and develop new medicines for neglected populations suffering from NTDs. Furthermore, there is not only a need to develop and evaluate novel therapies, but also to ensure that these are affordable, available, and adapted to the communities who need them. With this editorial, the British Pharmacological Society hereby launches a call for high-quality articles focusing on NTDs in special populations, to facilitate the reversal of this dual neglect.
Pharmacovigilance in Low and Middle-Income Countries: A review with particular focus...
Ronald Kiguba
Sten Olsson

Ronald Kiguba

and 2 more

September 25, 2021
Low- and middle-income countries (LMIC) face unique challenges with regard to the establishment of robust pharmacovigilance systems capable of generating data to inform healthcare policy and practice. These include the limited integration and reliance of pharmacovigilance systems across LMIC despite recent efforts to harmonize pharmacovigilance rules and regulations in several regional economic communities; the need to translate reporting tools into numerous local languages; low numbers of healthcare providers relative to number of patients, with very short consultation times; scarcity of well-trained pharmacovigilance personnel with little or no budgetary support for these activities from national governments; high turnover of pharmacovigilance staff whose training involves a substantial amount of resources; little awareness of pharmacovigilance among healthcare workers, decision makers and consumers; very low spontaneous reporting rates with poor quality reports which hinders robust signal detection analyses; little collaboration between public health programmes and national medicines regulatory authorities; limited investment in pharmacovigilance activities especially during mass drug administration for neglected tropical diseases; high uptake of herbal and traditional medication, mostly by self-medication; disruptive political conflicts jeopardizing fragile systems; and little or no access to drug utilization data which makes it difficult to reliably estimate the true safety risks of medicine use. This review summarises the specific challenges and areas of progress in pharmacovigilance in LMIC with special focus on the situation in Africa.
High-throughput phenotyping-based QTL mapping reveals the genetic architecture of the...
Guofang Zhang
Jinzhi Zhou

Guofang Zhang

and 20 more

September 25, 2021
Salt stress is a major limiting factor that severely affects the survival and growth of crops. It is important to understand the salt tolerance ability of Brassica napus and explore the underlying related genetic resources. We used a high-throughput phenotyping platform to quantify 2,111 image-based traits (i-traits) of a natural population under 3 different salt stress conditions and an intervarietal substitution line (ISL) population under 9 different stress conditions to monitor and evaluate the salt stress tolerance of B. napus over time. We finally identified 928 high-quality i-traits associated with the salt stress tolerance of B. napus. Moreover, we mapped the salt stress-related loci in the natural population via a genome-wide association study (GWAS) and performed a linkage analysis associated with the ISL population, respectively. The results revealed 234 candidate genes associated with salt stress response, and two novel candidate genes, BnCKX5 and BnERF3, were experimentally verified to regulate the salt stress tolerance of B. napus. This study demonstrates the feasibility of using high-throughput phenotyping-based QTL mapping to accurately and comprehensively quantify i-traits associated with B. napus. The mapped loci could be used for genomics-assisted breeding to genetically improve the salt stress tolerance of B. napus.
Robust estimates of cuticular conductance to water on a stomatous leaf surface
Jun Tominaga
Joseph Stinziano

Jun Tominaga

and 2 more

September 25, 2021
In leaf gas exchange measurements, cuticular conductance to water (gcw) is indistinguishable from and included in stomatal conductance to water vapor (gsw). Here we developed a simple technique to isolate gcw by directly measuring leaf intercellular CO2 concentration (Ci(m)) along with gas exchange during photosynthetic light induction. We derived stomatal conductance to CO2 (gsc(m)) from the Ci(m) independently of gsw. Plotting gsw against gsc(m) during the early induction phase within ~10 min, we found a highly linear relationship with a positive intercept. Assuming negligible cuticular CO2 transport, complete stomatal closure occurs when gsc(m)=0. Then, we considered the residual gsw (i.e., intercept) as gcw. Indeed, these gcw estimates succeeded in correcting the calculation. Our technique, owing to its robustness and increased throughput, will allow for more rapid screening of crops, more reliable gas exchange analysis, and more accurate prediction of plant function under natural environmental conditions.
Effects of climate change and pollen supplementation on the reproductive success of t...
Martin Andrzejak
Harald Auge

Martin Andrzejak

and 3 more

September 25, 2021
Climate change has the potential to alter plant reproductive success directly and indirectly through disruptions in animal pollination. Climate models project altered seasonal precipitation patterns and thus the effects of climate change on available resources and pollination services will depend on the season. Plants have evolved reproductive strategies to minimize pollen and resource limitations, and therefore we expect that the disruption of climate change might cause plants to be more pollen limited in seasons that become wetter than they were historically. In this study, we conducted a pollen supplementation experiment within the Global Change Experiment Facility (GCEF) in Central Germany. The GCEF experimentally manipulates future climate based on a realistic scenario of climate change for the region (drier summers and wetter springs and falls) in a native grassland ecosystem. We quantified seed production of two perennial species Dianthus carthusianorum and Scabiosa ochroleuca in response to pollination treatments (control, supplement), climate treatments (ambient and future) and season (summer and fall). Dianthus carthusianorum produced more seeds in future climate conditions independent of the season, but only when given supplemental pollen. Both species showed an increased reproduction in summer compared to the fall. We did not find any evidence for our expectation of higher pollen limitation in the future climate and fall season (i.e. no three-way interaction pollination x season x climate), which might be explained by the high drought tolerance and generalized pollination of our focal plant species. We conclude that plant reproductive success might be limited by the services of animal pollinators in future climates, and have many suggestions for future studies that are necessary to understand the context-dependence and underlying mechanisms of plant reproductive responses to climate.
Coinfection with a virus constrains within-host infection load but increases transmis...
Hanna Susi
Suvi Sallinen

Hanna Susi

and 2 more

September 25, 2021
The trade-off between within-host infection load and transmission to new hosts is predicted to constrain pathogen evolution, and to maintain polymorphism in pathogen populations. The life-history stages and their correlations that underpin infection development may change under coinfection with other parasites as they compete for the same limited host resources. Cross-kingdom interactions are common among pathogens in both natural and cultivated systems yet their impact on disease ecology and evolution are rarely studied. Host plant Plantago lanceolata is naturally infected by both Phompopsis subordinaria, a seed killing fungus, as well as Plantago lanceolata latent virus (PlLV) in the Åland Islands, SW Finland. We performed an inoculation assay to test whether coinfection with PlLV affects performance of two P. subordinaria strains, and the correlation between within-host infection load and transmission potential. The strains differed in the measured life-history traits and their correlations. Moreover, we found that under virus coinfection, within-host infection load of P. subordinaria was lower but transmission potential was higher compared to strains under single infection. The negative correlation between within-host infection load and transmission potential detected under single infection became positive under coinfection with PlLV. In wild populations, within-host infection load was positively associated with within-population disease prevalence. Jointly, our results suggest that the trade-off between within-host infection load and transmission may be strain specific, and that the pathogen life-history that underpin epidemics may change depending on the diversity of infection, generating variation in disease dynamics.
Influence of environmental variables on macroinvertebrate community structure in Lian...
Qianming Dou
Xue Du

Qianming Dou

and 7 more

September 25, 2021
The characteristics of macroinvertebrate community structure can effectively reflect the health status of lake ecosystem and the quality of the lake ecological environment. It is of great significance to identify the limiting factors of macroinvertebrate community structure for the maintenance of lake ecosystem health. In this study, the community composition of macroinvertebrate assemblages and their relationships with environmental variables in 13 small lakes within Linhuan Lake was investigated. Self-organizing map, K-means clustering analysis, principal component analysis, pearson correlation analysis, and redundancy analysis were used to analyze the correlation and variability between macroinvertebrates community index and environmental factors. The results showed that the environmental variables (pH, total phosphorus, nitrate, water temperature, dissolved oxygen, conductivity, chemical oxygen demand, and ammonium) had a significant effect on the classification of macroinvertebrate community. Molluscs were significantly negatively correlated with pH and chlorophyll a, while annelids and aquatic insects were significantly positively correlated with chlorophyll a and dissolved oxygen. Species richness and Shannon’s diversity of macroinvertebrates were significantly negatively correlated with total phosphorus while biomass of macroinvertebrates was significantly negatively correlated with pH. High alkalinity characteristics and eutrophication of the lake have a serious impact on the macroinvertebrate community. Human interference and unreasonable industrial and surface runoff from agricultural farms destroy the ecological environment and affect the community structure of macroinvertebrate. Thus, the improvement of the macroinvertebrate’s community structure should be carried out by improving the Lianhuan Lake watershed ecological environment and controlling watershed environmental pollution.
Breeding pattern of Oreochromis niloticus (Linnaeus, 1758) (Pisces: Cichlidae) versus...
Arthertone Jere
Wilson Jere

Arthertone Jere

and 3 more

September 25, 2021
Investigating the determinants of reproductive biology of fishes is an essential component of biological research. Breeding pattern was investigated to determine the impact of exotic Oreochromis niloticus on the native congeneric Oreochromis macrochir in the upper Kabompo River. Gonado-somatic index and sex ratio was used to investigate the breeding pattern in both invaded (where O. niloticus is present) and uninvaded (where O. niloticus is absent) sections of the river. Oreochromis macrochir was the only native congeneric species found in both sections. Results showed that the overall gonado-somatic index means for both sexes of O. macrochir in both sections were similar. For O. niloticus in invaded section indicated all year reproduction though reduced spawning in cold season (May-June), but with increased spawning activity in wet season (February-March). In O. macrochir, males and females were found breeding in both dry and wet seasons only, as for cold season no reproduction was recorded. Sex ratio (females: males) was 1:1.3 and 1:1.7 for O. niloticus and O. macrochir respectively, and both significantly deviated from the sex ratio of 1:1 (ꭓ2=8.42 and 9.37; p<0.05). Oreochromis niloticus formed the most abundant fish caught 221(63.5%) than O. macrochir 127(36.5%). Our study has revealed that O. niloticus was able to spawn in all seasons with 23% higher breeding population than O. macrochir, which explains the suppression in the abundance. We expect O. niloticus to invade further downstream of the Kabompo River due to natural dispersion.
Revisiting the influence of learning in predator functional response, how it can lead...
Octavio Bruzzone
María Aguirre

Octavio Bruzzone

and 4 more

September 25, 2021
Abstract Predator/Parasitoid functional response is one of the main tools used to study predation behaviour, and in assessing the potential of biological control candidates. It is generally accepted that predator learning in prey searching and manipulation can produce the appearance of type III functional response. Holling proposed that in the presence of alternative prey, at some point the predator would shift the preferred prey, leading to the appearance of a sigmoid function that characterized that functional response. This is supported by the analogy between enzyme kinetics and functional response that Holling used as the basis for developing this theory. However, after several decades, sigmoidal functional responses appear in the absence of alternative prey in most of the biological taxa studied. Here, we propose modelling the effect of learning on the functional response by using the explicit incorporation of learning curves in the parameters of the Holling functional response, the attack rate (a), and the manipulation time (h). We then study how the variation in the parameters of the learning curves causes variations in the shape of the functional response curve. We found that the functional response product of learning can be either type I, II or III, depending on what parameters act on the organism, and how much it can learn throughout the length of the study. Therefore the presence of other types of curves should not be automatically associated with the absence of learning. These results are important from an ecological point of view because when type III functional response is associated with learning, it is generally accepted that it can operate as a stabilizing factor in population dynamics. Our results, to the contrary, suggest that depending on how it acts, it may even be destabilizing by generating the appearance of functional responses close to type I.
Growth and Space-use of Eastern Red-backed Salamanders (Plethodon cinereus) in Mature...
Meaghan Gade
Philip Gould

Meaghan Gade

and 11 more

September 25, 2021
Movement and demographic rates are critical to the persistence of populations in space and time. Despite their importance, estimates of these processes are often derived from a limited number of populations spanning broad habitat or environmental gradients. With increasing appreciation of the role fine-scale environmental variation in microgeographic adaptation, there is need and value to assessing within-site variation in movement, growth, and demographic rates. In this study, we analyze three years of spatial capture-recapture data collected from a mixed-use deciduous forest site in central Ohio, USA. Study plots were situated in mature forest on a slope and in successional forest on a ridge but were separated by less than 100-m distance. Our data showed that the density of salamanders was less on ridges, which corresponded with greater distance between nearest neighbors, less overlap in core use areas, greater space-use, and greater shifts in activity centers when compared to salamander occupying the slope habitat. However, these differences were moderate. In contrast, we estimated growth rates of salamanders occupying the ridge to be significantly greater than salamander on the slope. These differences result in ridge salamanders reaching maturity more than one year earlier than slope salamanders, increasing their lifetime fecundity by as much as 43%. The patterns we observed in space use and growth are likely the result of density-dependent processes, reflecting differences in resource availability or quality. Our study highlights how fine-scale, within-site, variation can shape population demographics. As research into the demographic and population consequences of climate change and habitat loss and alteration continue, future research should take care to acknowledge the role that fine-scale variation may play, especially for organisms with small home ranges or limited vagility.
High species richness turnover of vascular epiphytes is associated with water availab...
Hazel Berrios
Indiana Coronado

Hazel Berrios

and 2 more

September 25, 2021
Research that has been conducted documenting species richness patterns on tropical mountains has resulted in conflicting observations: monotonic declines with increasing elevation, monotonic increase with increasing elevation, and a mid-elevation ‘bulge.’ Currently, it is unclear if these differences are due to environmental differences associated with the various study areas, the taxonomic groups or ecological groups (e.g., growth form) sampled, or the scale of the study area along an elevation gradient. Because of the difficulty in sampling and identifying canopy-dwelling plants, the number of inventories quantifying tropical epiphytes is relatively limited and recent. In this study, we provide a detailed qualitative and quantitative assessment of the vascular epiphyte flora and its spatial distribution on Volcán Maderas, Isla de Ometepe, Nicaragua, including weather and environmental measurements along the entire elevation gradient of the volcano. We sampled epiphytes in five distinct forest types associated with increasing elevation as follows: dry forest, humid forest, wet forest, cloud forest, and elfin forest Five weather stations were placed along the elevation gradient for us to relate observed patterns to environmental conditions. A hump-shaped species richness pattern was detected for all vascular epiphytes at approximately 1000 m in elevation (cloud forest), yet species abundance increased with increasing elevation. In total we obtained 206 unique species identifications of vascular epiphytes belonging to 26 families and 73 genera. The most species-rich family was the Orchidaceae with 55 species for the entire elevation gradient, followed by Bromeliaceae (29 species), Araceae (23), Polypodiaceae (25), Dryopteridaceae (16), and Piperaceae (11), with all other families respresented by fewer than 10 species each. We found that richness patterns differ phylogenetically within epiphytes, possibly due to different adaptive strategies, and species for the most part appear to be narrowly distributed within specific habitat zones along the elevation gradient.
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