Ecological correlates of elevational range shifts in tropical birds

Globally, birds have been shown to respond to climate change by shifting their elevational distributions. This phenomenon is especially prevalent in the tropics, where elevational gradients are often hotspots of diversity and endemism. Empirical evidence has suggested that elevational range shifts are far from uniform across species, varying greatly in the direction (upslope vs. downslope) and rate of change (speed of elevational shift). However, little is known about the drivers of these variable responses to climate change, limiting our ability to accurately project changes in the future. Here, we compile empirical estimates of elevational shift rates (m/yr) for 421 bird species from eight study sites across the tropics. On average, species shifted their mean elevations upslope by 1.63 ± 0.30 m/yr, their upper limits by 1.62 m ± 0.38 m/yr, and their lower limits by 2.81 ± 0.42 m/yr. Upslope shift rates increased in smaller-bodied, less territorial species, whereas larger species were more likely to shift downslope. When considering absolute shift rates, rates were fastest for species with high dispersal ability, low foraging strata, and wide elevational ranges. Our results indicate that elevational shift rates are associated with species’ traits, particularly body size, dispersal ability, and territoriality. However, these effects vary substantially across sites, suggesting that responses of tropical montane bird communities to climate change are complex and best predicted within the local or regional context

Teaching Through Collaboration: Flexibility and Diversity in Caregiver–Child Interaction Across Cultures

Supporting Information is available online at https://srcd.onlinelibrary.wiley.com/doi/10.1111/cdev.13443#support-information-section .Teaching supports the high-fidelity transmission of knowledge and skills. This study examined similarities and differences in caregiver teaching practices in the United States and Vanuatu (N = 125 caregiver and 3- to 8-year-old child pairs) during a collaborative problem-solving task. Caregivers used diverse verbal and nonverbal teaching practices and adjusted their behaviors in response to task difficulty and child age in both populations. U.S. caregivers used practices consistent with a direct active teaching style typical of formal education, including guiding children’s participation, frequent praise, and facilitation. In contrast, Ni-Vanuatu caregivers used practices associated with informal education and divided tasks with children based on difficulty. The implications of these findings for claims about the universality and diversity of caregiver teaching are discussed.Economic and Social Research Council. Grant Number: REF RES-060-25-0085; National Science Foundation. Grant Number: 173067

Structural diversity in alkali metal and alkali metal magnesiate chemistry of the bulky 2,6-diisopropyl-N-(trimethylsilyl)anilino ligand

Bulky amido ligands are precious in s-block chemistry since they can implant complementary strong basic and weak nucleophilic properties within compounds. Recent work has shown the pivotal importance of the base structure with enhancement of basicity and extraordinary regioselectivities possible for cyclic alkali metal magnesiates containing mixed n-butyl/amido ligand sets. This work advances alkali metal and alkali metal magnesiate chemistry of the bulky aryl-silyl amido ligand [N(SiMe3)(Dipp)] (Dipp = 2,6-iPr2-C6H3). Infinite chain structures of the parent sodium and potassium amides are disclosed, adding to the few known crystallographically characterised unsolvated s-block metal amides. Solvation by PMDETA or TMEDA gives molecular variants of the lithium and sodium amides; whereas for potassium, PMDETA gives a molecular structure but TMEDA affords a novel, hemi-solvated infinite chain. Crystal structures of the first magnesiate examples of this amide in [MMg{N(SiMe3)(Dipp)}2(μ-nBu)]∞ (M = Na or K), are also revealed though these breakdown to their homometallic components in donor solvent as revealed through NMR and DOSY studies

Losartan to slow the progression of mild-to-moderate Alzheimer's disease through angiotensin targeting: the RADAR RCT

BACKGROUND: Medications that modify the renin–angiotensin system may reduce Alzheimer’s disease pathology and reduce the rate of disease progression. OBJECTIVE: This study investigated whether taking the antihypertensive drug losartan, in addition to normal care, would slow the progression of Alzheimer’s disease when compared with a placebo. DESIGN: A double-blind multicentre randomised controlled trial, after a 4-week open-label phase, with follow-up at 14 days and at 3, 6, 9 and 12 months. The primary outcome was based on measured imaging differences in brain volume between baseline and 12 months. SETTING: Twenty-three NHS hospital trusts across England, Scotland and Northern Ireland. PARTICIPANTS: Patients diagnosed with mild-to-moderate Alzheimer’s disease were eligible to participate if they met the following criteria: (1) aged ≥ 55 years; (2) a Mini Mental State Examination score of 15–28; (3) a modified Hachinski Ischaemic Score of ≤ 5; (4) a previous computerised tomography, single-photon emission computed tomography or magnetic resonance imaging scan consistent with a diagnosis of Alzheimer’s disease; (5) a study companion who was willing to participate in the study; and (6) capacity to consent for themselves. Patients were ineligible if they were (1) taking or intolerant to renin–angiotensin system-related medications, (2) unlikely to undergo magnetic resonance imaging or (3) unlikely to complete the trial protocol. People who had blood pressure outside the normal ranges, defined cardiovascular issues, impaired liver or renal function, or a primary neurodegenerative disease that was not Alzheimer’s disease were also excluded, as were women who had not reached menopause and were unwilling to take relevant protocol-specific safety precautions. INTERVENTION: The intervention was either 100 mg of overencapsulated losartan (Teva Pharmaceuticals Industries Ltd, Petah Tikva, Israel) daily or a matched placebo for 12 months. MAIN OUTCOMES AND MEASURES: Difference in brain atrophy, represented by measurement of whole-brain volume before and following 12 months of treatment post randomisation, was measured using volumetric MRI and determined by boundary shift interval analysis. Secondary outcomes included changes in rates of Alzheimer’s disease progression (as assessed using the ADAS-Cog, Mini Mental State Examination and Neuropsychiatric Inventory), the volume of white matter hyperintensities, cerebral blood flow (assessed by magnetic resonance imaging), blood pressure, magnetic resonance imaging measures of atrophy and association with measures of cognitive decline, and drug compliance and tolerability. RESULTS: A total of 261 participants entered the open-label phase, of whom 211 were randomised to the intervention (n = 105) or placebo (n = 106) arms. Of the 197 people (93%) who completed the study, 81% (n = 171) had a valid primary outcome. The difference in brain volume between arms was consistent with chance (–2.79 ml, 95% confidence interval –6.46 to 0.89 ml; p = 0.19), and there was no evidence of benefit for any of the secondary outcome measures. LIMITATIONS: Our study had 82% power to detect treatment-based changes and, as a result, may have been underpowered or, more likely, the intervention, which may not have crossed the blood–brain barrier as much as expected, may have been given too late or for an insufficient amount of time in the disease process to influence the outcomes. CONCLUSIONS: Losartan administered over 12 months did not alter brain atrophy in Alzheimer’s disease. FUTURE WORK: Other related ‘sartans’ could be tested in patient groups with mild cognitive impairment and for longer to fully test this hypothesis. TRIAL REGISTRATION: Current Controlled Trials ISRCTN93682878 and EudraCT 2012-003641-15. FUNDING: This project was funded by the Efficacy and Mechanism Evaluation (EME) programme, a Medical Research Council and National Institute for Health Research (NIHR) partnership. This will be published in full in Efficacy and Mechanism Evaluation; Vol. 8, No. 19. See the NIHR Journals Library website for further project information

Cell-Type Specific Expression of a Dominant Negative PKA Mutation in Mice

We employed the Cre recombinase/loxP system to create a mouse line in which PKA activity can be inhibited in any cell-type that expresses Cre recombinase. The mouse line carries a mutant Prkar1a allele encoding a glycine to aspartate substitution at position 324 in the carboxy-terminal cAMP-binding domain (site B). This mutation produces a dominant negative RIα regulatory subunit (RIαB) and leads to inhibition of PKA activity. Insertion of a loxP-flanked neomycin cassette in the intron preceding the site B mutation prevents expression of the mutant RIαB allele until Cre-mediated excision of the cassette occurs. Embryonic stem cells expressing RIαB demonstrated a reduction in PKA activity and inhibition of cAMP-responsive gene expression. Mice expressing RIαB in hepatocytes exhibited reduced PKA activity, normal fasting induced gene expression, and enhanced glucose disposal. Activation of the RIαB allele in vivo provides a novel system for the analysis of PKA function in physiology

Malnutrition Has No Effect on the Timing of Human Tooth Formation

The effect of nutrition on the timing of human tooth formation is poorly understood. Delays and advancements in dental maturation have all been reported as well as no effect. We investigated the effect of severe malnutrition on the timing of human tooth formation in a large representative sample of North Sudanese children. The sample (1102 males, 1013 females) consisted of stratified randomly selected healthy individuals in Khartoum, Sudan, aged 2-22 years using a cross-sectional design following the STROBE statement. Nutritional status was defined using WHO criteria of height and weight. Body mass index Z-scores and height for age Z-scores of ≤-2 (cut-off) were used to identify the malnourished group (N = 474) while the normal was defined by Z-scores of ≥0 (N = 799). Clinical and radiographic examination of individuals, with known ages of birth was performed including height and weight measurements. Mandibular left permanent teeth were assessed using eight crown and seven root established tooth formation stages. Mean age at entry and mean age within tooth stages were calculated for each available tooth stage in each group and compared using a t-test. Results show the mean age at entry and mean age within tooth stages were not significantly different between groups affected by severe malnutrition and normal children (p>0.05). This remarkable finding was evident across the span of dental development. We demonstrate that there is little measurable effect of sustained malnutrition on the average timing of tooth formation. This noteworthy finding supports the notion that teeth have substantial biological stability and are insulated from extreme nutritional conditions compared to other maturing body systems

Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA

An investigation of the hadronic final state in diffractive and non--diffractive deep--inelastic electron--proton scattering at HERA is presented, where diffractive data are selected experimentally by demanding a large gap in pseudo --rapidity around the proton remnant direction. The transverse energy flow in the hadronic final state is evaluated using a set of estimators which quantify topological properties. Using available Monte Carlo QCD calculations, it is demonstrated that the final state in diffractive DIS exhibits the features expected if the interaction is interpreted as the scattering of an electron off a current quark with associated effects of perturbative QCD. A model in which deep--inelastic diffraction is taken to be the exchange of a pomeron with partonic structure is found to reproduce the measurements well. Models for deep--inelastic $ep$ scattering, in which a sizeable diffractive contribution is present because of non--perturbative effects in the production of the hadronic final state, reproduce the general tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil

A Search for Selectrons and Squarks at HERA

Data from electron-proton collisions at a center-of-mass energy of 300 GeV are used for a search for selectrons and squarks within the framework of the minimal supersymmetric model. The decays of selectrons and squarks into the lightest supersymmetric particle lead to final states with an electron and hadrons accompanied by large missing energy and transverse momentum. No signal is found and new bounds on the existence of these particles are derived. At 95% confidence level the excluded region extends to 65 GeV for selectron and squark masses, and to 40 GeV for the mass of the lightest supersymmetric particle.Comment: 13 pages, latex, 6 Figure

Study of e+e- --> pi+ pi- pi0 process using initial state radiation with BABAR

The process e+e- --> pi+ pi- pi0 gamma has been studied at a center-of-mass energy near the Y(4S) resonance using a 89.3 fb-1 data sample collected with the BaBar detector at the PEP-II collider. From the measured 3pi mass spectrum we have obtained the products of branching fractions for the omega and phi mesons, B(omega --> e+e-)B(omega --> 3pi)=(6.70 +/- 0.06 +/- 0.27)10-5 and B(phi --> e+e-)B(phi --> 3pi)=(4.30 +/- 0.08 +/- 0.21)10-5, and evaluated the e+e- --> pi+ pi- pi0 cross section for the e+e- center-of-mass energy range 1.05 to 3.00 GeV. About 900 e+e- --> J/psi gamma --> pi+ pi- pi0 gamma events have been selected and the branching fraction B(J/psi --> pi+ pi- pi0)=(2.18 +/- 0.19)% has been measured.Comment: 21 pages, 37 postscript figues, submitted to Phys. Rev.