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A Series of Crystallographically Characterized Linear and Branched σ-Alkane Complexes of Rhodium: From Propane to 3-Methylpentane
No full textUsing solid-state molecular organometallic (SMOM) techniques, in particular solid/gas single-crystal to single-crystal reactivity, a series of σ-alkane complexes of the general formula [Rh(Cy PCH CH PCy )(η :η -alkane)][BAr ] have been prepared (alkane = propane, 2-methylbutane, hexane, 3-methylpentane; Ar = 3,5-(CF ) C H ). These new complexes have been characterized using single crystal X-ray diffraction, solid-state NMR spectroscopy and DFT computational techniques and present a variety of Rh(I)···H-C binding motifs at the metal coordination site: 1,2-η :η (2-methylbutane), 1,3-η :η (propane), 2,4-η :η (hexane), and 1,4-η :η (3-methylpentane). For the linear alkanes propane and hexane, some additional Rh(I)···H-C interactions with the geminal C-H bonds are also evident. The stability of these complexes with respect to alkane loss in the solid state varies with the identity of the alkane: from propane that decomposes rapidly at 295 K to 2-methylbutane that is stable and instead undergoes an acceptorless dehydrogenation to form a bound alkene complex. In each case the alkane sits in a binding pocket defined by the {Rh(Cy PCH CH PCy )} fragment and the surrounding array of [BAr ] anions. For the propane complex, a small alkane binding energy, driven in part by a lack of stabilizing short contacts with the surrounding anions, correlates with the fleeting stability of this species. 2-Methylbutane forms more short contacts within the binding pocket, and as a result the complex is considerably more stable. However, the complex of the larger 3-methylpentane ligand shows lower stability. Empirically, there therefore appears to be an optimal fit between the size and shape of the alkane and overall stability. Such observations are related to guest/host interactions in solution supramolecular chemistry and the holistic role of 1°, 2°, and 3° environments in metalloenzymes
Exploring the Boundaries of Ambient RF Energy Harvesting With LoRaWAN
No full text—Environmental monitoring is an important
application for wireless sensing devices. Battery power requires in-the-field replacement, and the chemicals involved are environmentally harmful, so harvested energy is a useful alternative. Previous research has shown the feasibility of powering LoRaWAN sensors using high-energy ambient or wireless transfer power sources. This article extends this work by exploring the boundaries of using low-energy radio-frequency (RF) ambient sources. Ambient RF energy harvesting is an attractive option, but it is more challenging due to the low levels of energy density typically available. Using an analytical LoRaWAN device model and RF energy data collected from around the world, a systematic investigation of the design and environmental space is performed. The main contribution of this article is to identify the boundaries of feasibility for powering LoRaWAN sensor nodes from ambient RF energy. These boundaries include design and environmental factors
Making of Wellbeing Measurement:
No full textIn this paper, we propose a ‘study protocol’ for researching the becomings of the Danish national wellbeing survey for schools. We engage with the idea of a published research protocol that originates from positivist research paradigms and medical research in particular. Within these paradigms, protocol serves the purpose of ensuring the objectivity and replicability of the research in question, and provides a sense of security to the researcher in terms of the quality of the research design. In contrast, with ideas of transmethodology in mind, we suggest a protocol that endeavours to support researchers to engage with ambiguity, uncertainty and singularity in research while still being attentive to quality. We suggest a protocol that helps de-stabilize the concept of wellbeing in schools and looks at how wellbeing as an object of measurement is (re)configured, who the human and non-human actors involved are, and what effects their assembling produces. These questions require research practices that acknowledge the complexities of the human condition and the richness of the social and material world. Instead of suggesting a “paradigm shift”, we are inspired by Patti Lather, who argues for a proliferation of paradigms, where proliferation refers to forming a pattern of interference. In other words, proliferation calls for reflection on the inconsistencies, confusion, disorganization of the research process, and both our need and caution to position ourselves epistemologically and ontologically. The protocol we suggest deploys diverse, sometimes complementary, sometimes contrasting methods, analytical strategies or theoretical perspectives in order to explore the problem at hand and engage with the ironies, tensions and uncertainties inherent to research
‘What Kind of Education System are We Offering’: The Views of Education Professionals on School Refusal
No full textIn recent years, there has been a growing concern about the issue of school refusal, particularly given the adverse effects on young people’s social, emotional and educational development. School refusal is understood differently within contemporary literature; as a symptom of an underlying mental illness or disorder, or alternatively, as a signal that all is not well in the young person’s world. These varying construal’s have important implications for education responses to school refusal. This study explores education professionals' views and experiences of school refusal within second level schools in Ireland. The findings from seventeen in-depth interviews highlight the complex nature of school refusal and unique challenges it presents for professionals, young people and parents. Key themes include emotional and psychological distress experienced by young people and their exposure to adverse childhood experiences and trauma; the influence of family socio economic status and unequal access to support services and resources; the pressures for academic achievement and resulting conflictual relationships within the school environment and between home and school. This study highlights the need for trauma-informed approaches in schools and urges future research to consider school refusal within wider debates on social justice and the goals and purposes of education
The IRX(3)some factor in macrophages
No full textObesity is a major global healthcare concern, with over 600 million adults worldwide currently classified as living with the condition1. Obesity has been linked to numerous comorbid
conditions ranging from type 2 diabetes mellitus and cardiovascular disease to a high percentage of cancers2
. A core link between obesity and these comorbidities is chronic inflammation3 , and thus the quest to understand the initiators and drivers of this pathogenic process in people
with obesity is critically important and may lead to future therapeutics. In this issue of Nature Immunology, Qiu and colleagues identify the transcription factor IRX3 as a
key driver of pro-inflammatory cytokine production in macrophages, which in mouse models is associated with repression of lipolysis and thermogenesis, leading
to increased bodyweight and poor metabolic health4
Differential proteomic response of Agaricus bisporus and Trichoderma aggressivum f. europaeum to Bacillus velezensis supernatant
No full textTrichoderma aggressivum, a mycopathogen
causing green mould disease, is a major problem in
Agaricus bisporus cultivation due to crop loss, and
resistance to chemical fungicides. There is an urgent
need for novel biological ways to control mycopathogens without affecting the growth of A. bisporus. Bacteria from the mushroom-casing environment were identified and tested for antagonistic effect on T. aggressivum. Bacillus velezensis produced a large zone of inhibition and its supernatant inhibited the growth of T. aggressivum [−37%], and slightly stimulated A. bisporus growth [+2%]. Label free quantitative proteomic (LFQ) analysis of changes in the abundance of T. aggressivum proteins following exposure to
B. velezensis supernatant indicated increased abundance
of proteins associated with catabolic processing of amino acids (40-fold), amino oxidase proteins (14-fold),
oxidoreductase proteins (13-fold, 4-fold) and hydrolases
(3-fold). Proteins that decreased in relative abundance
were antioxidants (29-fold), NTF2 domain containing
protein (17-fold), 60S ribosomal protein L-13 (14-fold),
glucoamylase proteins (13-fold), proteasome subunit
proteins (11-fold) and other ribosomal proteins (9-fold).
LFQ analysis revealed that exposing A. bisporus to
B. velezensis supernatant led to a decrease in: prohibitin
(13-fold, 6-fold), proteasomal proteins (11-fold), cytosolic adaptor domain containing protein (5-fold), aldehyde dehydrogenase (4-fold), ribosomal proteins (4-
fold), DLH domain-containing protein (4-fold) and
PKS_ER domain containing protein (3-fold). The results indicate that A. bisporus was not under stress upon
contact with B. velezensis. Whereas a detrimental effect
of B. velezensis on T. aggressivum is shown by inhibition of growth and damage-preventing proteins and
increased abundance of proteins associated with stress
An Improved Method for the Estimation and Comparison of Mortality Rates in Fish from Catch‐Curve Data
No full textCatch-curve analyses are routinely used to estimate instantaneous mortality (Z) in fish, and as the age-frequency data are often over dispersed, the application of a variance bias-correction factor has been recommended. The extensions of the Poisson generalized linear model (GLMPoisson) may, however, constitute a better alternative, as they model the variance (SE) in counts more adequately with their specific dispersion parameter for more accurate estimations and statistical comparisons. To test this idea, simulated age-frequency data generated under four dispersion scenarios were analyzed according to six currently available methods and compared with the results of a GLMPoisson and
five of its extensions to evaluate each method-specific bias in Z SE estimates. Empirical age-frequency data from
sampled Walleye Sander vitreus and Arctic Char Salvelinus alpinus populations in Quebec, Canada, were then used ´
to illustrate the applicability of our GLM-based method, which relies on the behavior of Pearson residuals to assess
model adequacy and an information-theoretic approach for model selection. All analyses revealed that Z-estimates
were generally accurate among the methods considered, except under the most likely situation of quadratic over dispersion met in ecological studies, for which only the negative binomial type 2 and the mean-parametrized Conway–
Maxwell–Poisson (CMP) extensions were adequate to estimate both Z and its SE. Linearly over dispersed data were
best modeled by the negative binomial type 1 and generalized Poisson (GLMGP) extensions; the GLMCMP and
GLMGP were the most appropriate to model under dispersed data, whereas the GLM Poisson adequately modeled equi- dispersed data, similar to the Chapman and Robson (1960) method. Statistical comparisons of Z SE for grouping
factors, such as year or site, were correctly achieved when the most adequate and statistically supported GLM Poisson
extension was applied. Altogether, the proposed GLM-based method should help to circumvent the identified issues
related to SE estimation for statistical inferences about mortality rates for fisheries management decision making
Depression reported by US adults in 2017–2018 and March and April 2020
No full textBackground: Coronavirus disease 2019 (COVID-19) and the associated social distancing and lockdown restrictions are expected to have substantial and enduring mental health effects. In this study, we aimed to assess
depression levels before and during the COVID-19 pandemic in the United States.
Methods: We used the Patient Health Questionnaire-2 (PHQ-2) brief screening instrument to detect probable
depression in two nationally representative surveys of US adults. Pre-pandemic levels of depression were assessed in a sample of 5,075 adults from the 2017–2018 National Health and Nutrition Examination Survey
(NHANES). Depression was assessed in March (N = 6,819) and April 2020 (N = 5,428) in the Understanding
America Study, a representative sample of the US population.
Results: The percentage of US adults with depression increased significantly from 8.7% (95% CI[7.6%–9.8%]) in
2017–2018 to 10.6% (95% CI[9.6%–11.6%) in March 2020 and 14.4% (95% CI[13.1%–15.7%]) in April 2020.
Statistically significant increases in depression levels were observed for all population subgroups examined with
the exception of those aged 65+ years and Black participants. Young adults (aged 18–34) experienced a marked
increase in depression of 13.4 percentage points (95% CI [9.5%–17.2%]) that was larger than any other age
group. Additional analyses of depression trends in NHANES from 2007/2008–2017/2018 showed that the
substantial increase in depression in April 2020 was unlikely to be due to typical year-to-year variation.
Conclusions: Our findings suggest that depression levels have risen substantially during the COVID-19 pandemic
and reinforce recent findings indicating that young adults may be particularly vulnerable to the mental health
effects of the pandemic
Anxiety reported by US adults in 2019 and during the 2020 COVID-19 pandemic: Population-based evidence from two nationally representative samples
No full textBackground: : The impact of the coronavirus disease 2019 (COVID-19) on the mental health of the US population
is unclear. This study drew on two nationally representative samples to compare the prevalence rate of anxiety in
the U.S. before and during the 2020 COVID-19 pandemic.
Methods: : The Generalized Anxiety Disorder-2 (GAD-2) screening tool was used to detect the proportion of US
adults screening positive for high levels of anxiety symptoms. Anxiety symptoms was assessed in 2019 using the
National Health Interview Survey (NHIS; N = 30,915) and during the pandemic using biweekly surveys collected
as part of the Understanding America Study (UAS; N=8,022 Obs.=121,768) between March and December 2020.
Results: : The proportion of participants with high levels of anxiety symptoms increased significantly from 8.1%
(95% CI[7.7, 8.5]) in 2019 to 21.4% (95% CI[19.9, 22.9]) at the beginning of April, 2020. The prevalence then
declined to 11.4% (95% CI[10.3, 12.5]) in May and remained 3% above 2019 levels until December 2020. This
pattern of increasing anxiety between 2019 and April 2020 followed by a rapid decrease in anxiety was identified
across all demographic characteristics examined.
Limitations: : The NHIS and UAS samples differ in their sampling and mode of administration which may bias
comparisons between samples.
Conclusions: : Anxiety symptoms increased markedly during the onset of the COVID-19 pandemic and reduced
quickly as stay-at-home orders were lifted. These findings highlight the importance of providing mental health
supports during future lockdowns and suggest that resilience in mental health may have been a key population level response to the demands of the pandemic
Zombies Vs Unicorns: An Exploration of the Pleasures of the Gothic for Young Adults
No full textThe abstract is included in the text