501 research outputs found
The Potential Impact of Climate Change on the Distributions of \u3ci\u3eEleutherodactylus cystignathoides\u3c/i\u3e and \u3ci\u3eE. planirostris\u3c/i\u3e (Anura: Eleutherodactylidae)
Climate change is inducing changes in the distributions of many species, causing range shifts and habitat loss as well as facilitating invasions. It is a broad contributor to global amphibian decline, already causing mass extinctions and extirpations of amphibian populations, a phenomenon which is expected to continue. The understudied direct-developing frog Eleutherodactylus cystignathoides is a notable outlier, having rapidly expanded its distribution in recent years. This is of particular interest given that other eleutherodactylids, such as E. coqui and E. planirostris, have already shown propensity for rapid dispersal and invasion. Originally found in the southernmost tip of Texas, USA and northeastern Mexico, E. cystignathoides has established populations far into northeastern Texas, in addition to southern Louisiana, USA, and Alabama, USA. This expansion has been assumed to be ecologically neutral due to lack of evidence of negative impact, but no confirmational investigation has occurred. The dearth of information about this species’ dispersal and ecology, coupled with the documented negative impacts of other successful eleutherodactylid invaders, warrants investigation that preempts waiting for any potential consequences of this geographical expansion to make themselves known. To conduct an investigation into the potential range limits of this species as they are defined by bioclimatic variables, we used spatially rarefied occurrences and selected future climate models to develop Maxent projections of potentially suitable habitat of E. cystignathoides. These methods were repeated with the better-studied congener E. planirostris, a Cuban frog with an introduced range from Florida to Texas, for the purposes of contextualization and comparison. Our models suggest the existence of currently non-invaded potentially suitable habitat across the southeastern USA under both current and future models for E. cystignathoides, but widespread range contractions for E. planirostris. The models additionally predict habitat loss in the native ranges of each species under future climate conditions
Stoichiometry control of sputtered CuCl thin films: Influence on ultraviolet emission properties
We demonstrate that the chemical composition of the sputtered CuCl thin films could be finely controlled by adjusting the bias to the substrate. The films deposited without any intentional bias were Cl rich (CuCl1+x), a bias of −22 V yielded stoichiometric CuCl, and a further increase in the negative bias resulted in Cl deficient films (CuCl1−x). The crystalline and optical properties were found to be associated with the chemical composition. Cl rich films showed a deep level green emission at around 515 nm in addition to ultraviolet (UV) excitonic emission. The stoichiometric films have higher optical quality, exhibiting a sharp UV emission at around 385 nm at room temperature, compared to nonstoichiometric samples. Visible luminescence related to deep level defects was not observed in the stoichiometric films. Changes in energy of the flux from the target and the subsequent ion bombardment on the substrate surface are correlated with the variations in chemical composition and their impact on the film microstructure and UV emission
Self-concealment: Integrative review and working model
An extensive empirical literature has focused on the self-concealment (SC) construct. In this article, we review 137 studies that used the Self-Concealment Scale (SCS) with varied populations (e.g., adolescent; intercultural; international; lesbian, gay, and bisexual; and intimate partner). We propose a working model for the psychology of SC and the mechanisms of action for its effects on well-being. A dual-motive conflict between urges to conceal and reveal is seen to play a central role in these health effects. Meta-analytic techniques identify significant associations for SC with 18 constructs falling into six general categories: antecedents, disclosure and concealment, emotion regulation, social well-being, psychological and physical health, and psychotherapy. We interpret these findings with reference to current research and theory on secret keeping and health as well as emotion- and self-regulatory processes. This first integrative review supports the construct validity of the SCS and demonstrates the value of the SC construct for the study of psychological phenomena in which secret keeping is a recognized issue
Cryptococcosis in a patient with multiple myeloma receiving pomalidomide: a case report and literature review
While overall survival with multiple myeloma (MM) has improved, patients suffer from overwhelming tumor burden, MM-associated comorbidities, and frequent relapses requiring administration of salvage therapies. As a result, this vicious cycle is often characterized by cumulative immunodeficiency stemming from a combination of disease- and treatment-related factors leading to neutropenia, T-cell deficiency, and hypogammaglobulinemia. Infectious etiologies differ based on the duration of MM and treatment-related factors, such as number of previous treatments and cumulative dose of corticosteroids. Herein, we present the case of a patient who was receiving pomalidomide without concomitant corticosteroids for MM and was later found to have cryptococcosis, as well as findings from a literature review. Most cases of cryptococcosis are reported in patients with late-stage MM, as well as those receiving novel anti-myeloma agents, such as pomalidomide, in combination with corticosteroids or following transplantation. However, it is likely cryptococcosis may be underdiagnosed in this population. Due to the cumulative immunodeficiency present in patients with MM, clinicians must be suspicious of cryptococcosis at any stage of MM
Maize leaf PPDK regulatory protein isoform-2 is specific to bundle sheath chloroplasts and paradoxically lacks a Pi-dependent PPDK activation activity
In C4 plants, the pyruvate phosphate dikinase regulatory protein (PDRP) regulates the C4 pathway enzyme pyruvate phosphate dikinase (PPDK) in response to changes in incident light intensity. In maize (Zea mays) leaves, two distinct isoforms of PDRP are expressed, ZmPDRP1 and ZmPDRP2. The properties and C4 function of the ZmPDRP1 isoform are well understood. However, the PDRP2 isoform has only recently been identified and its properties and function(s) in maize leaves are unknown. We therefore initiated an investigation into the maize PDRP2 isoform by performing a side by side comparison of its enzyme properties and cell-specific distribution with PDRP1. In terms of enzyme functionality, PDRP2 was found to possess the same protein kinase-specific activity as PDRP1. However, the PDRP2 isoform was found to lack the phosphotransferase activity of the bifunctional PDRP1 isoform except when PDRP2 in the assays is elevated 5- to 10-fold. A primarily immuno-based approach was used to show that PDRP1 is strictly expressed in mesophyll cells and PDRP2 is strictly expressed in bundle sheath strand cells (BSCs). Additionally, using in situ immunolocalization, we establish a regulatory target for PDRP2 by showing a significant presence of C4 PPDK in BSC chloroplasts. However, a metabolic role for PPDK in this compartment is obscure, assuming PPDK accumulating in this compartment would be irreversibly inactivated each dark cycle by a monofunctional PDRP2
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Effects of elevated CO2 and temperature on seed quality
Successful crop production depends initially on the availability of high-quality seed. By 2050 global climate change will have influenced crop yields, but will these changes affect seed quality? The present review examines the effects of elevated carbon dioxide (CO₂) and temperature during seed production on three seed quality components: seed mass, germination and seed vigour.
In response to elevated CO₂, seed mass has been reported to both increase and decrease in C₃ plants, but not change in C₄ plants. Increases are greater in legumes than non-legumes, and there is considerable variation among species. Seed mass increases may result in a decrease of seed nitrogen (N) concentration in non-legumes. Increasing temperature may decrease seed mass because of an accelerated growth rate and reduced seed filling duration, but lower seed mass does not necessarily reduce seed germination or vigour.
Like seed mass, reported seed germination responses to elevated CO₂ have been variable. The reported changes in seed C/N ratio can decrease seed protein content which may eventually lead to reduced viability. Conversely, increased ethylene production may stimulate germination in some species. High-temperature stress before developing seeds reach physiological maturity (PM) can reduce germination by inhibiting the ability of the plant to supply the assimilates necessary to synthesize the storage compounds required for germination.
Nothing is known concerning the effects of elevated CO₂ on seed vigour. However, seed vigour can be reduced by high-temperature stress both before and after PM. High temperatures induce or increase the physiological deterioration of seeds. Limited evidence suggests that only short periods of high-temperature stress at critical seed development stages are required to reduce seed vigour, but further research is required.
The predicted environmental changes will lead to losses of seed quality, particularly for seed vigour and possibly germination. The seed industry will need to consider management changes to minimize the risk of this occurring.This is the publisher’s final pdf. The published article is copyrighted by Cambridge University Press and can be found at: http://www.cambridge.org/.Keywords: Physiological maturity, Hollow heart, Population density, Germination, Air temperature, Carbon dioxide, Pea Pisum sativum, Reproductive growth, Vigor, Annual plantsKeywords: Physiological maturity, Hollow heart, Population density, Germination, Air temperature, Carbon dioxide, Pea Pisum sativum, Reproductive growth, Vigor, Annual plant
Nodal dynamics, not degree distributions, determine the structural controllability of complex networks
Structural controllability has been proposed as an analytical framework for
making predictions regarding the control of complex networks across myriad
disciplines in the physical and life sciences (Liu et al.,
Nature:473(7346):167-173, 2011). Although the integration of control theory and
network analysis is important, we argue that the application of the structural
controllability framework to most if not all real-world networks leads to the
conclusion that a single control input, applied to the power dominating set
(PDS), is all that is needed for structural controllability. This result is
consistent with the well-known fact that controllability and its dual
observability are generic properties of systems. We argue that more important
than issues of structural controllability are the questions of whether a system
is almost uncontrollable, whether it is almost unobservable, and whether it
possesses almost pole-zero cancellations.Comment: 1 Figures, 6 page
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