Let‘s talk about… different things! Communication within and among sexes in Farasan gazelles

Scent marking in localized defecation sites (latrines) has often been interpreted in the context of male territory defense. Still, latrines could have different functions in both sexes, especially where territorial males monopolize groups of females with stable social alliances. We assessed the spatial distribution of latrines within home ranges of wild ranging Arabian gazelles (Gazella arabica) on Farasan Island (Red Sea, Saudi Arabia)

Microstructure and mechanical properties of sintered (2-4)Mn-(0¿6.-0¿8)C steels

YesMechanical properties of 2¿4% manganese PM steels were determined in tension and in bending following laboratory sintering in dry, hydrogen rich atmospheres. Young's modulus determined by an extensometric technique was about 115 GPa; when measured by an ultrasonic method it was about 153 GPa, in accordance with the`law of mixtures¿. The microstructures, significantly devoid of oxide networks, were predominantly pearlitic, but frequently with variability for specimens similarly processed, resulting in appreciable variations in the stresses for macroscopic yielding and fracture. The majority of the experiments were conducted on 3 and 4Mn¿0·6C alloys and for these R0·1 was in the range 275¿500 MPa, tensile strength (TS) 300¿600 MPa, and (apparent) transverse rupture strength (TRS) 640¿1260 MPa. Statistical techniques were employed to analyse the data. When careful control of processing was maintained, the Weibull modulus was highest, at about 17, for TS of furnace cooled specimens, and lowest, about 6, for TRS of the rapidly cooled specimens. In order to interpret the significant differences between the TRS and the TS values, both apparently measuring the critical stress for cracking after strains of up to 7%, a two stage normalising technique for TRS was adopted. By taking account of the plastic strains preceding failure, the elastic`strength of materials¿ formula was modified to allow true fracture stresses to be calculated. It was also postulated that failure was initiated from a population of flaws of variable size and then the `normalised¿ bend strengths, smaller than TRSs, were shown to correspond well with TSs. It is suggested that this combined plasticity correction and Weibull analysis approach, which has a sound scientific basis, should be employed to interpret bend test data in preference to empirical correlations between TS and TRS

Age-dependent mating tactics in male bushbuck (Tragelaphus scriptus)

Intra-specific variation in mating behaviour has been described for a number of taxa including arthropods, fishes, amphibians, reptiles, birds and mammals. Several mechanisms have been proposed to explain the various mating behavioural variations observed in mammals. For example, an individual’s behaviour may be constrained by its condition or status (making-the- best of-a-bad-job strategy) or an alternative phenotype may be maintained by frequency-dependent selection influencing a genetic polymorphism (alternative strategies). In the majority of ungulates, variation in mating tactics is most likely maintained as a conditional strategy influenced by multiple internal factors like age, health or body size, as well as external factors such as population density, number of competitors and social dominance rank. In the present study, we investigated male mating tactics in a cryptic, bush-dwelling antelope from tropical Africa, the bushbuck, Tragelaphus scriptus (Figures.1, 2). Different mating strategies are expected to emerge, if variation in mating tactic is maintained as a conditional strategy influenced by age and / or body size: 1) Defending a territory when old and strong, what allows the owner to associating more frequently with females within the combined territory and home-range area. 2) No territory defence when young and weak, thereby associating with females less frequently and therefore sneak-mating with them

Sintering microstructure and mechanical properties of PM manganese-molybdenum steels

YesThe effects of 0·5 wt-%Mo addition on the processing, microstructure, and strength of PM Fe¿3·5Mn¿0·7C steel are described. Water atomised and sponge irons, Astaloy 1·5Mo, milled ferromanganese, and graphite were the starting powders. During sintering in 75H2 /25N2 or pure hydrogen the dewpoint was controlled and monitored; in particular the effects of improving it from -35 to -60°C were investigated. Faster heating rates (20 K min-1), sufficient gas flowrates, milling the ferro alloy under nitrogen, a low dewpoint (<-60°C), and a getter powder can all contribute to the reduction or prevention of oxidation of the manganese, in particular formation of oxide networks in the sintered steels. For 600 MPa compaction pressure densities up to 7·1 g cm-3 were obtained; these were not significantly affected by sintering at temperatures up to 1180°C. The sintered microstructures were sensitively dependent on the cooling rate. Irrespective of the presence of Mo, slow furnace cooling at 4 K min-1 resulted in mainly pearlitic structures with some ferrite and coarse bainite, whereas fast cooling at 40 K min-1 produced martensite and some retained austenite, very fine pearlite, bainite, and some ferrite. Young's modulus, determined by tensile and ultrasonic tests, was in the range 110¿155 GPa. Sintering with -60°C dewpoint resulted in tensile and transverse rupture strengths of420 and 860 MPa for the Mn steel, rising to 530 and1130 MPa as a result of the Mo addition. This contrasts with strength decreases observed when processing included use of high oxygen containing ferromanganese and sintering with -35°C dewpoint

Tensile properties of Fe-3Mn-0¿6/0¿7C steels sintered in semiclosed containers in dry hydrogen, nitrogen and mixtures thereof

Ye

A Tale of Two Democrats: How Authoritarianism Divides the Democratic Party

Authoritarianism has been predominantly used in American politics as a predictor of Republican identification and conservative policy preferences. We argue that this approach has neglected the role authoritarianism plays among Democrats and how it can operate within political parties regardless of their ideological orientation. Drawing from three distinct sets of data, we demonstrate the impact of authoritarianism in the 2016 Democratic Party’s primaries. Authoritarianism consistently predicts differences in primary voting among Democrats, particularly support for Hillary Clinton over Bernie Sanders. This effect is robust across various model specifications including controls for ideology, partisan strength, and other predispositions. These results highlight the potential of authoritarianism to shape leadership preferences within the Democratic Party. We advocate for a reconsideration of authoritarianism as a disposition with meaningful consequences for intraparty dynamics and conclude with practical implications regarding the future of the Democratic Party

Barking up the wrong biomarker? Correspondence to Shobeiri et al. (2022) “Serum and plasma levels of brain-derived neurotrophic factor in individuals with eating disorders (EDs): a systematic review and meta-analysis”

Despite intensified research efforts into the underlying (neuro-)biology of eating disorders (EDs), only few reliable biomarkers of diagnostic or prognostic value have been identified to date. One promising line of research has focused on the role of peripheral blood-based biomarkers as potential contributors to the complex pathophysiology of EDs. One such candidate marker is brain-derived neurotrophic factor (BDNF), a neurotrophin broadly implicated in neuronal plasticity and food-intake regulation. A growing number of studies have targeted BDNF in EDs; culminating in several recent well-powered and controlled case–control studies, comprehensive meta-analyses, and review articles. In the current correspondence, we aim to put the recent meta-analysis of Shobeiri et al. (J Eat Disord 10(1):105, 2022) into perspective and argue that the finding suggestive of lower BDNF concentrations across individuals with EDs in comparison to healthy controls needs to be interpreted with caution. While this finding is compatible with those from earlier meta-analyses, it may be biased due to several reasons; most notably by the applied study selection procedures, insufficient consideration of influential determinants of BDNF concentrations, and generalization of results across the ED spectrum without sufficient statistical power. Further controlled and comprehensive studies are necessary to establish BDNF as a clinically informative biomarker of EDs

Recovery of Ungulate Populations in Post-Civil War Akagera National Park, Rwanda

Following the 1991–1995 civil war in Rwanda, large parts of Akagera National Park (NP) and the adjacent Mutara Game Reserve were endowed by government to returning war refugees for cattle grazing. In 1997, official degazettement reduced the area covered by these two protected areas by 60% (from 2800 km2 to 1120 km2). This study reports trends in population sizes and densities of ungulates in modern Akagera NP (1120 km2), with a focus on the more common ungulates (impala, topi, zebra, buffalo, waterbuck, and warthog). Data from previous surveys are compared with our 2010–2014 road strip counts using distance sampling. A decline of ungulate populations during the civil war, followed by recovery several years after reduction of the size of the Park, is evident. The ungulate populations show different trends in size in recent years, suggesting that the carrying capacity has been reached for some species