155 research outputs found
The efficiency of nitrogen stabilizer at different soil temperatures on the physiological development and productivity of maize (Zea mays L.)
Received: January 29th, 2021 ; Accepted: October 8th, 2021 ; Published: October 20th, 2021 ; Correspondence: [email protected] (N) stabilizer containing nitrapyrin inhibitor is responsible for slowing the
activity of Nitrosomonas sp. bacteria down which oxidize ammonium to nitrite ions, thus, N-loss
resulting from nitrate leaching can be reduced. Although prior studies have shown its
effectiveness in the pre-sowing application in maize, considering that it disturbs the activity of
Nitrosomonas bacteria which is the most intense between 25 °C and 30 °C, soil temperature may
significantly influence the efficiency of nitrapyrin. Besides, nitrapyrin aims to enhance N-use
efficiency in high N-demanding plants, such as maize, which demands N at the most during stalk
elongation, which lays down the reason for its subsequent application. This study focuses on the
efficiency of nitrapyrin at different soil temperatures and its impacts on the physiological
development and productivity of maize. In a laboratory test, 10 °C, 15 °C, 20 °C, and 25 °C
temperature soils were treated with nitrapyrin and change of nitrate content was monitored to
observe the nitrification dynamic. Results show that as the soil temperature elevated, the
inhibition efficiency increased. In a field experiment with maize, nitrapyrin was applied in 13 °C
and 25 °C temperature soil. Results suggest the later treatment enhanced N-use efficiency, as,
during the high N-demanding growth stage, more N-forms were available in the soil. This resulted
in significantly higher relative chlorophyll concentration in the leaves and laboratory leaf analysis
confirmed the prevention of N deficiency. Results of further measurements on parameters
indicating biomass production such as root mass, stalk diameter, ear size, 1,000-kernel weight
indicate that the nitrapyrin application should be timed later
Viewpoint paper. Islander mobilities: any change from climate change?
Climate change is stated as being likely to cause the forced movement of millions of people, especially from small island communities. Such statements are not always placed in wider and deeper understandings of mobility and non-mobility. Focusing on island communities, this paper assesses some of the implications inherent in mobility and non-mobility choices related to climate change in comparison to other factors and drivers. Culture and networks are examples of drivers demonstrating that it is not the norm for climate change to dominate mobility and non-mobility choices by islanders. Instead, choices often arise from social factors which, in turn, impact how climate change is and is not addressed. Without denying the major challenges which climate change has previously brought to some islanders and brings to many islanders today, climate change nonetheless brings little substantive change to discussions of islander mobilities
Characteristics of strong midwifery leaders and enablers of strong midwifery leadership:An international appreciative inquiry
Objectives: This research aimed to identify the characteristics of strong midwifery leaders and explore how strong midwifery leadership may be enabled from the perspective of midwives and nurse-midwives globally. Design: In this appreciative inquiry, we collected qualitative and demographic data using a cross-sectional online survey between February and July 2022.Setting: Responses were received from many countries (n = 76), predominantly the United Kingdom (UK), Australia, the United States of America (USA), Canada, Uganda, Saudi Arabia, Tanzania, Rwanda, India, and Kenya. Participants: An international population (n = 429) of English-speaking, and ethnically diverse midwives (n = 211) and nurse-midwives (n = 218).Measurements: Reflexive thematic analysis was used to make sense of the qualitative data collected. Identified characteristics of strong midwifery leadership were subsequently deductively mapped to established leadership styles and leadership theories. Demographic data were analysed using descriptive statistics. Findings: Participants identified strong midwifery leaders as being mediators, dedicated to the profession, evidence-based practitioners, effective decision makers, role models, advocates, visionaries, resilient, empathetic, and compassionate. These characteristics mapped to compassionate, transformational, servant, authentic, and situational leadership styles. To enable strong midwifery leadership, participants identified a need for investment in midwivesâ clear professional identity, increased societal value placed upon the midwifery profession, ongoing research, professional development in leadership, interprofessional collaborations, succession planning and increased self-efficacy. Key conclusions and implications for practice: This study contributes to understandings of trait, behavioural, situational, transformational and servant leadership theory in the context of midwifery. Investing in the development of strong midwifery leadership is essential as it has the potential to elevate the profession and improve perinatal outcomes worldwide. Findings may inform the development of both existing and new leadership models, frameworks, and validated measurement tools
El yacimiento de Colata (Montaverner, Valencia) y los 'poblados de silos' del IV milenio en las comarcas centro-meridionales del PaĂs Valenciano
Les estructures documentades al jaciment de Colata (Montaverner, ValÚncia) mostren la parcialitat del registre que caracteritza aquest tipus de jaciment a l'aire lliure del IV mil·lenni aC, cosa que obliga a plantejar noves estratÚgies per a reinterpretar l¿evolució en les conductes d'emmagatzematge, consum i producció d'aliments, i en la organització social d'aquestes comunitats. Paraules'clau: Vall d'Albaida. Estructures excavades. Poblats de sitges. Patró d'assentament. Organització social
Bartonella rochalimae in Raccoons, Coyotes, and Red Foxes
To determine additional reservoirs for Bartonella rochalimae, we examined samples from several wildlife species. We isolated B. rochalimae from 1 red fox near Paris, France, and from 11 raccoons and 2 coyotes from California, USA. Co-infection with B. vinsonii subsp. berkhoffii was documented in 1 of the coyotes
Intracellular growth of Mycobacterium tuberculosis after macrophage cell death leads to serial killing of host cells
A hallmark of pulmonary tuberculosis is the formation of macrophage-rich granulomas. These may restrict Mycobacterium tuberculosis (Mtb) growth, or progress to central necrosis and cavitation, facilitating pathogen growth. To determine factors leading to Mtb proliferation and host cell death, we used live cell imaging to track Mtb infection outcomes in individual primary human macrophages. Internalization of Mtb aggregates caused macrophage death, and phagocytosis of large aggregates was more cytotoxic than multiple small aggregates containing similar numbers of bacilli. Macrophage death did not result in clearance of Mtb. Rather, it led to accelerated intracellular Mtb growth regardless of prior activation or macrophage type. In contrast, bacillary replication was controlled in live phagocytes. Mtb grew as a clump in dead cells, and macrophages which internalized dead infected cells were very likely to die themselves, leading to a cell death cascade. This demonstrates how pathogen virulence can be achieved through numbers and aggregation states. DOI: http://dx.doi.org/10.7554/eLife.22028.00
T cell derived HIV-1 is present in the CSF in the face of suppressive antiretroviral therapy.
HIV cerebrospinal fluid (CSF) escape, where HIV is suppressed in blood but detectable in CSF, occurs when HIV persists in the CNS despite antiretroviral therapy (ART). To determine the virus producing cell type and whether lowered CSF ART levels are responsible for CSF escape, we collected blood and CSF from 156 neurosymptomatic participants from Durban, South Africa. We observed that 28% of participants with an undetectable HIV blood viral load showed CSF escape. We detected host cell surface markers on the HIV envelope to determine the cellular source of HIV in participants on the first line regimen of efavirenz, emtricitabine, and tenofovir. We confirmed CD26 as a marker which could differentiate between T cells and macrophages and microglia, and quantified CD26 levels on the virion surface, comparing the result to virus from in vitro infected T cells or macrophages. The measured CD26 level was consistent with the presence of T cell produced virus. We found no significant differences in ART concentrations between CSF escape and fully suppressed individuals in CSF or blood, and did not observe a clear association with drug resistance mutations in CSF virus which would allow HIV to replicate. Hence, CSF HIV in the face of ART may at least partly originate in CD4+ T cell populations
An Overview of Research and Evaluation Designs for Dissemination and Implementation
The wide variety of dissemination and implementation designs now being used to evaluate and improve health systems and outcomes warrants review of the scope, features, and limitations of these designs
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Characterisation of Immune and Neuroinflammatory Changes Associated with Chemotherapy-Induced Peripheral Neuropathy
Chemotherapy-induced peripheral neuropathy (CIPN) and associated neuropathic pain is a debilitating adverse effect of cancer treatment. Current understanding of the mechanisms underpinning CIPN is limited and there are no effective treatment strategies. In this study, we treated male C57BL/6J mice with 4 cycles of either Paclitaxel (PTX) or Oxaliplatin (OXA) over a week and tested pain hypersensitivity and changes in peripheral immune responses and neuroinflammation on days 7 and 13 post 1st injection. We found that both PTX and OXA caused significant mechanical allodynia. In the periphery, PTX and OXA significantly increased circulating CD4+ and CD8+ T-cell populations. OXA caused a significant increase in the percentage of interleukin-4+ lymphocytes in the spleen and significant down-regulation of regulatory T (T-reg) cells in the inguinal lymph nodes. However, conditional depletion of T-reg cells in OXA-treated transgenic DEREG mice had no additional effect on pain sensitivity. Furthermore, there was no leukocyte infiltration into the nervous system of OXA- or PTX-treated mice. In the peripheral nervous system, PTX induced expression of the neuronal injury marker activating transcription factor-3 in IB4+ and NF200+ sensory neurons as well as an increase in the chemokines CCL2 and CCL3 in the lumbar dorsal root ganglion. In the central nervous system, PTX induced significant astrocyte activation in the spinal cord dorsal horn, and both PTX and OXA caused reduction of P2ry12+ homeostatic microglia, with no measurable changes in IBA-1+ microglia/macrophages in the dorsal and ventral horns. We also found that PTX induced up-regulation of several inflammatory cytokines and chemokines (TNF-α, IFN-γ, CCL11, CCL4, CCL3, IL-12p70 and GM-CSF) in the spinal cord. Overall, these findings suggest that PTX and OXA cause distinct pathological changes in the periphery and nervous system, which may contribute to chemotherapy-induced neuropathic pain
Rare Germline DICER1 Variants in Pediatric Patients With Cushing's Disease: What Is Their Role?
Context: The DICER1 syndrome is a multiple neoplasia disorder caused by germline mutations in the DICER1 gene. In DICER1 patients, aggressive congenital pituitary tumors lead to neonatal Cushing's disease (CD). The role of DICER1 in other corticotropinomas, however, remains unknown.
Objective: To perform a comprehensive screening for DICER1 variants in a large cohort of CD patients, and to analyze their possible contribution to the phenotype.
Design, setting, patients, and interventions: We included 192CD cases: ten young-onset (age <30 years at diagnosis) patients were studied using a next generation sequencing panel, and 182 patients (170 pediatric and 12 adults) were screened via whole-exome sequencing. In seven cases, tumor samples were analyzed by Sanger sequencing.
Results: Rare germline DICER1 variants were found in seven pediatric patients with no other known disease-associated germline defects or somatic DICER1 second hits. By immunohistochemistry, DICER1 showed nuclear localization in 5/6 patients. Variant transmission from one of the parents was confirmed in 5/7 cases. One patient had a multinodular goiter; another had a family history of melanoma; no other patients had a history of neoplasms.
Conclusions: Our findings suggest that DICER1 gene variants may contribute to the pathogenesis of non-syndromic corticotropinomas. Clarifying whether DICER1 loss-of-function is disease-causative or a mere disease-modifier in this setting, requires further studies.This work was supported by the Intramural Research Programs of Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and National Institute for Neurological Diseases and Stroke, National Institutes of Health, a grant from the Basque Department of Education (IT795-13), a grant from the Basque Department of Health (GV2018111082), the Merck Serono Research award from Fundacion Salud 2000 (15-EP-004) and the Jose Igea 2018 grant, sponsored by Pfizer, from Fundacion Sociedad Espanola de Endocrinologia Pediatrica (SEEP)
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