Search

An increase in the frequency and intensity of catastrophic wildfires is associated with anthropogenic climate change. Wildfires are extreme environmental events that result in dramatic fluctuations in temperature and moisture, which are likely to disproportionately impact animals such as amphibians (Anura) whose distributions and ecology are strongly tied to climate. In response to the 2019/20 Australian summer wildfires, we used expert elicitation to analyse the traits of frogs that potentially influence fire sensitivity or resilience. Traits that were ranked high in terms of influencing fire sensitivity were range size, dominant adult habitat, reproductive mode, and relative abundance. While species restricted to cool, moist habitats are less exposed to the threat of wildfire, they had the highest sensitivity scores. This is due to their typically low fecundity, reliance on micro-refugia away from water for reproduction and shelter, and small, isolated distributions. The group considered least sensitive were those which occupy riparian zones as macro-refugia, which includes species with wide geographic distributions, general reproductive strategies, high fecundity, and moderate physiological capacity. Our findings suggest that it is the behavioural capacity of frogs to locate micro-refugia, a morphology that enables them to move into these safe spaces, and physiological adaptations to subsequently maintain water balance during and after wildfire that influence the probability of surviving wildfire. While many traits have evolved among amphibians to avoid climatic extremes and likely confer resistance to wildfire as “exaptations”, it remains unknown to what extent they protect populations from predicted hotter and drier climates. Our predictions should be tested by obtaining direct measures of the thermal and moisture buffering capacities of micro-refuges, along with the continued monitoring of species recovery post-fire, so that they can feedback into future trait-based analyses. We suggest that strategic management actions for mitigating the effect of climate-driven wildfires on amphibians should involve protection and enhancement of micro-refugia components of the landscape, which are used as shelter during times of heat and moisture stress, and provision of buffer zones around macro-refugia habitat, such as around streams.

Context Drones, or remotely piloted aircraft systems, equipped with thermal imaging technology (RPAS thermal imaging) have recently emerged as a powerful monitoring tool for koala populations. Before wide uptake of novel technologies by government, conservation practitioners and researchers, evidence of greater efficiency and cost-effectiveness than with other available methods is required. Aims We aimed to provide the first comprehensive analysis of the cost-effectiveness of RPAS thermal imaging for koala detection against two field-based methods, systematic spotlighting (Spotlight) and the refined diurnal radial search component of the spot-assessment technique (SAT). Methods We conducted various economic comparisons, particularly comparative cost-effectiveness of RPAS thermal imaging, Spotlight and SAT for repeat surveys of a low-density koala population. We compared methods on cost-effectiveness as well as long-term costs by using accumulating cost models. We also compared detection costs across population density using a predictive cost model. Key results Despite substantial hardware, training and licensing costs at the outset (>A$49 900), RPAS thermal imaging surveys were cost-effective, detecting the highest number of koalas per dollar spent. Modelling also suggested that RPAS thermal imaging requires the lowest survey effort to detect koalas within the range of publicly available koala population densities (~0.006–18 koalas ha−1) and would provide long-term cost reductions across longitudinal monitoring programs. RPAS thermal imaging would also require the lowest average survey effort costs at a landscape scale (A$3.84 ha−1), providing a cost-effective tool across large spatial areas. Conclusions Our analyses demonstrated drone thermal imaging technology as a cost-effective tool for conservation practitioners monitoring koala populations. Our analyses may also form the basis of decision-making tools to estimate survey effort or total program costs across any koala population density. Implications Our novel approach offers a means to perform various economic comparisons of available survey techniques and guide investment decisions towards developing standardised koala monitoring approaches. Our results may assist stakeholders and policymakers to confidently invest in RPAS thermal imaging technology and achieve optimal conservation outcomes for koala populations, with standardised data collection delivered through evidence-based and cost-effective monitoring programs.

Identifying which species exhibit polyandry may lead to further insights into evolutionary biology and social behaviour. However, confirming polyandry can be difficult. High-resolution genetics provides a useful means to gain evidence. Although the threatened Pelodryadid frog, the green and golden bell frog Litoria aurea, has been subject to numerous ecological studies, there is uncertainty surrounding its reproductive ecology. Polyandry has not been formally identified in L. aurea or any species within the Pelodryadidae family. We aimed to identify if there was genetic evidence of polyandry in a population occurring in a wetland complex on Kooragang Island, New South Wales. To accomplish this, we collected genetic samples of tadpoles within the same size cohort about 20-30 days after explosive breeding events. Genotypes of 14 females, nine males and 70 tadpoles were analysed with COLONY (1988 single nucleotide polymorphisms after filtering) to identify parentage, full-siblings and half-siblings. We found support for the hypothesis that L. aurea is polyandrous. Based on previous observations of multi-male matings and the narrow time periods that breeding occurred in, it is likely this species exhibits simultaneous polyandry. We discuss these results in regards to behavioural adaptive processes and avenues for further research.

We describe a 226 km range extension for the known distribution of the Western Soil-Crevice Skink Proablepharus reginae in Western Australia. This record from Cape Range National Park is the first for this species on the North West Cape and within the Cape Range IBRA sub-region and marks the most westerly record of P. reginae for mainland Australia. This finding raises the terrestrial reptile species richness for the Cape Range peninsula to 90. Previous surveys in this area failed to detect P. reginae, which demonstrates the value of repeated surveys in documenting species richness in remote locations. Furthermore, we provide morphological and ecological data and discuss this record in the contexts of geographic variation and the high number of isolated reptile populations and endemism seen on the Cape Range peninsula.

Habitat restoration is an integral feature of wildlife conservation. However, funding and opportunities for habitat restoration are limited, and therefore, it is useful for targeted restoration to provide positive outcomes for non‐target species. Here, we investigate the possibility of habitat creation and management benefitting two threatened wetland specialists: the Green and Golden Bell Frog (Litoria aurea) and the Large‐footed Myotis (Myotis macropus). This study involved two components: (i) assessing co‐occurrence patterns of these species in a wetland complex created for the Green and Golden Bell Frog (n = 9) using counts, and (ii) comparing foraging activity of Large‐footed Myotis in wetlands with low and high aquatic vegetation (n = 6 and 7, respectively) using echolocation metres. Since Large‐footed Myotis possesses a unique foraging behaviour of trawling for aquatic prey, we hypothesised that foraging activity of this species would be higher in wetlands with low aquatic vegetation coverage. Additionally, we provide observations of its potential prey items. We identified one created wetland where both species were found in relatively high numbers, and this wetland had a permanent hydrology, was free of the introduced fish Gambusia (Gambusia holbrooki) and had low aquatic vegetation coverage. We also found that Myotis feeding activity was significantly higher in low aquatic vegetation coverage wetlands (x = 65.72 ± 27.56 SE) compared to high (x = 0.33 ± 0.33 SE, P = 0.0000). Although this is a preliminary study, it seems likely that Green and Golden Bell Frog and Large‐footed Myotis would gain mutual benefit from wetlands that are constructed to be permanent, that are Gambusia free, low in aquatic vegetation coverage, and are located in close to suitable roosting habitat for Large‐footed Myotis. We encourage adaptive aquatic vegetation removal for Green and Golden Bell frog as this may have benefits for Large‐footed Myotis. The evidence suggests that the former may be a suitable umbrella species for the latter.

Here, we identify an easily implemented wetland design feature that can prolong tadpole survival of the threatened Green and Golden Bell Frog (Litoria aurea). We observed small depressions that naturally formed within some wetlands following the construction of habitat for this species. We observed that wetlands containing depressions prolonged the survival of Green and Golden Bell Frog tadpoles during periods of rapid wetland drying whereas wetlands that did not contain depressions in the same circumstances dried, causing 100% mortality in tadpoles present. We recommend that this concept be considered as a design feature in future wetland construction for Green and Golden Bell Frog and other ephemeral wetland breeding amphibians and we provide commentary on how the benefits of this feature can be maximised. This simple design feature may be important for amphibian restoration, particularly considering climate change.

Remotely piloted aircraft system (RPAS), or drone, technology has emerged as a promising survey method for the cryptic koala. We demonstrate an in-field protocol for wild koala RPAS surveys which provides real-time validation of thermal signatures. During 15 trial flights using a quadcopter drone (DJI Matrice 200 v2) we successfully detected and validated koala thermal signatures (n = 12) using two in-field approaches: validation by on-ground observer (n = 10) and validation using 4K footage captured and reviewed directly after the survey (n = 2). We also provide detectability considerations relative to survey time, temperature, wildlife–RPAS interactions and detection of non-target species, which can be used to further inform RPAS survey protocols.

Biodiversity is in global decline during the Anthropocene. Declines have been caused by multiple factors, such as habitat removal, invasive species, and disease, which are often targets for conservation management. However, conservation interventions are under threat from climate change induced weather extremes. Weather extremes are becoming more frequent and devastating and an example of this was the 2019/2020 Australian drought and mega-fires. We provide a case study the impacts of these extreme weather events had on a population of the threatened frog Litoria aurea that occurs in a constructed habitat which was designed to reduce the impact of introduced fish and chytrid-induced disease. We aimed to determine what factors influenced persistence so that the design of wetlands can be further optimised to future-proof threatened amphibians. We achieved this with 4 years (2016–2020) of intensive capture–recapture surveys during austral spring and summer across nine wetlands (n = 94 repeat surveys). As hypothesized, drought caused a sharp reduction in population size, but persistence was achieved. The most parsimonious predictor of survival was an interaction between maximum air temperature and rainfall, indicating that weather extremes likely caused the decline. Survival was positively correlated with wetland vegetation coverage, positing this is an important feature to target to enhance resilience in wetland restoration programs. Additionally, the benefits obtained from measures to reduce chytrid prevalence were not compromised during drought, as there was a positive correlation between salinity and survival. We emphasize that many species may not be able to persist under worse extreme weather scenarios. Despite the potential for habitat augmentation to buffer effects of extreme weather, global action on climate change is needed to reduce extinction risk.

Amphibians are under threat from many drivers resulting in declining populations. Restoration and creation of habitat is a method used to reverse amphibian declines. The green and golden bell frog (Litoria aurea) is distributed in southeastern Australia, and is threatened by the fungal pathogen Batrachochytrium dendobatidis (chytrid), an introduced fish (the plague minnow, Gambusia holbrooki), and habitat loss. There have been numerous wetland restoration attempts to combat population declines in this species, which have been largely unsuccessful in producing persisting populations. Here we present a robust model for the creation of breeding habitat for the L. aurea population on Kooragang Island, New South Wales, which is based off thorough review of the literature and past pilot studies and experiments. We describe in detail the habitat, land use history, and wetland habitat design formulation and construction so that the context of the habitat creation is understood and so construction can be repeatable and the design can be further refined. The habitat features passive controls for chytrid and G. holbrooki, and contains the most optimum breeding habitat for L. aurea based upon current knowledge. This is the first attempt in our knowledge to create wetlands in an open system that have the potential to passively manage chytrid.

Relatedness (rxy) measures are useful in molecular ecology studies as they can provide a means to answer biological hypotheses where pedigree information is valuable. Our understanding of the reproductive ecology of the threatened amphibian Litoria aurea is not complete where applying rxy measurements may provide further elucidation. Here we use SNPs to identify which rxy estimators (or combination of) most precisely assign relationships in L. aurea tadpoles to determine how many breeding pairs contribute to producing propagules in explosive breeding events. We aimed to (1) use simulated L. aurea genotype data to determine the precision of six rxy estimators, (2) compare the precision of relationship assignment thresholds between rxy estimators computed by discriminant function analysis (DFA) and test if using multiple estimators improved precision, and (3) Apply the best performing DFA model to assign relationships in wild tadpoles to quantify how many mating pairs reproduced in explosive breeding events. We hypothesised that each tadpole cohort produced during explosive breeding events would be conceived by >|2| mating pairs. The triadic maximum likelihood estimator had the highest Pearson’s R2 (0.92) and the lowest amount of misclassifications in the DFA (16.00%). A multi-variate DFA that included three rxy estimators further reduced the misclassifications down to 11.88%. There was evidence that more than one mating pair contributed to each explosive breeding event (n = 11). We show that the multi-variate DFA enabled precise relationship classification of free-living tadpoles which improved knowledge on amphibian reproductive ecology. We recommend this method for relationship assignments in SNP genotyped datasets.

An inverse relationship between egg and clutch size has been found repeatedly across animal groups, including birds, reptiles and amphibians, and is considered to be a result of resource limitations and physical constraints on the reproducing female. However, few studies have contextualised this relationship with respect to various environmental selecting pressures and life history traits that have also likely influenced the selection of an optimal egg/clutch size combination, while even fewer have tested these interrelationships using robust natural history datasets. In this study, we aimed to test current hypothesises regarding these relationships on both egg and clutch sizes among the Australian Anurans, which to date have not received this kind of investigation. Specifically, we looked at the influence of environmental selecting pressures (egg laying location, environment persistence and bioregion) and life history traits (adult female body size, egg development type, parental care level, breeding period and temporal breeding pattern). As expected, a clear inverse relationship was found between egg and clutch size, while female body size was positively related to both. Generally speaking, smaller clutches of larger eggs tended to be produced by species that i) oviposit terrestrially, ii) showcase direct development and iii) possess high levels of parental care. Temporal breeding pattern was strongly related to clutch size only, with large clutches occurring in explosive breeding species, while breeding habitat was strongly related to egg size only, with large eggs sizes occurring in terrestrial species. Altogether, these findings indicate that numerous factors have likely influenced the evolution of an optimal clutch type in this group, highlighting the importance of incorporating such variables into animal studies on egg and clutch sizes.

The ‘Compassionate Conservation’ movement is gaining momentum through its promotion of ‘ethical’ conservation practices based on self-proclaimed principles of ‘first-do-no-harm’ and ‘individuals matter’. We argue that the tenets of ‘Compassionate Conservation’ are ideological - that is, they are not scientifically proven to improve conservation outcomes, yet are critical of the current methods that do. In this paper we envision a future with ‘Compassionate Conservation’ and predict how this might affect global biodiversity conservation. Taken literally, ‘Compassionate Conservation’ will deny current conservation practices such as captive breeding, introduced species control, biocontrol, conservation fencing, translocation, contraception, disease control and genetic introgression. Five mainstream conservation practices are used to illustrate the far-reaching and dire consequences for global biodiversity if governed by ‘Compassionate Conservation’. We acknowledge the important role of animal welfare science in conservation practices but argue that ‘Compassionate Conservation’ aligns more closely with animal liberation principles protecting individuals over populations. Ultimately we fear that a world of ‘Compassionate Conservation’ could stymie the global conservation efforts required to meet international biodiversity targets derived from evidenced based practice, such as the Aichi targets developed by the Convention on Biological Diversity and adopted by the International Union for the Conservation of Nature and the United Nations. Fil: Callen, Alex. Universidad de Newcastle; Australia Fil: Hayward, Matt W.. Universidad de Newcastle; Australia. Nelson Mandela University; Sudáfrica. Universidad de Pretoria; Sudáfrica Fil: Klop Toker, Kaya. Universidad de Newcastle; Australia Fil: Allen, Benjamin L.. University of Queensland; Australia Fil: Ballard, Guy. University of New England Australia; Australia. University of New South Wales; Australia Fil: Beranek, Chad T.. Universidad de Newcastle; Australia. Universidad de Pretoria; Sudáfrica Fil: Broekhuis, Femke. University of Oxford; Reino Unido Fil: Bugir, Cassandra K.. Universidad de Newcastle; Australia. Universidad de Pretoria; Sudáfrica Fil: Clarke, Rohan H.. Monash University; Australia Fil: Clulow, John. Universidad de Newcastle; Australia Fil: Clulow, Simon. Universidad de Newcastle; Australia. Macquarie University; Australia Fil: Daltry, Jennifer C.. Fauna & Flora International; Reino Unido Fil: Davies Mostert, Harriet T.. Universidad de Pretoria; Sudáfrica. Endangered Wildlife Trust; Sudáfrica Fil: Di Blanco, Yamil Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; Argentina Fil: Dixon, Victoria. Universidad de Newcastle; Australia Fil: Fleming, Peter J. S.. University of Queensland; Australia. University of New England; Australia. University of New South Wales; Australia Fil: Howell, Lachlan G.. Universidad de Newcastle; Australia Fil: Kerley, Graham I. H.. Nelson Mandela University; Sudáfrica Fil: Legge, Sarah M.. Australian National University, Fenner School Of Environment And Society; Australia. University of Queensland; Australia Fil: Lenga, Dean J.. Universidad de Newcastle; Australia Fil: Major, Tom. Bangor University; Reino Unido Fil: Montgomery, Robert A.. Michigan State University; Estados Unidos Fil: Moseby, Katherine. University of New South Wales; Australia Fil: Meyer, Ninon. Fondation Yaguara Panama; Panamá Fil: Parker, Dan M.. University of Mpumalanga; Sudáfrica. Rhodes University.; Sudáfrica Fil: Périquet, Stéphanie. Ongava Research Centre; Sudáfrica Fil: Read, John. University of Adelaide; Australia Fil: Scanlon, Robert J.. Universidad de Newcastle; Australia Fil: Shuttleworth, Craig. Bangor University; Reino Unido. Red Squirrel Trust Wales; Reino Unido Fil: Tamessar, Cottrell T.. Universidad de Newcastle; Australia Fil: Taylor, William Andrew. Endangered Wildlife Trust; Sudáfrica Fil: Tuft, Katherine. Arid Recovery; Australia Fil: Upton, Rose M. O.. Universidad de Newcastle; Australia Fil: Valenzuela, Marcia. Universidad de Newcastle; Australia. Instituto Politécnico Nacional. Centro de Investigación y de Estudios Avanzados. Departamento de Fisica.; México Fil: Witt, Ryan R.. Universidad de Newcastle; Australia Fil: Wüster, Wolfgang. Bangor University; Reino Unido

Amphibians have declined due to multiple impacts including invasive fish and the disease chytridiomycosis caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). Wetland restoration can be used to increase amphibian populations. However the design of created wetlands must account for threats such as Bd and introduced fish. There have been no attempts on a landscape level to manage these threats with habitat design. Here we monitored the green and golden bell frog (Litoria aurea) in 2.6 ha of constructed wetlands designed to enhance breeding and increase survival through passive mitigation of Bd and exotic fish. We compared the fecundity, adult population sizes, introduced fish occupancy, Bd prevalence and survival rates of frogs in created wetlands (CW) to three control sites to determine if and why the habitat design was successful. Monitoring involved weekly capture-recapture during the austral spring and summer for three L. aurea breeding seasons. We hypothesised that (1) if the CWs were successful in passively limiting fish colonisation, a larger number of breeding events would be detected compared to control sites which are known to be widely colonised by introduced fish. (2) If the wetlands were successful in passively mitigating Bd, then we would observe an equal or greater survival rate and equal to or lower Bd prevalence compared to control wetlands. We observed a 3.3-fold increase in adult population size in CW from season 1 to 2, and the population increased further in season 3.We found strong support for hypothesis (1) and weak support for (2). Based on these results, we conclude that this design was beneficial shortly after their formation primarily due to fish exclusion, but further study is required to determine if these benefits extend long-term. Future amphibian restoration studies are needed to improve the design of wetlands to enhance suppression of Bd.

Although the Little Eagle Hieraaetus morphnoides is broadly distributed across much of Australia, it appears to be declining in New South Wales. The key threatening process is the removal of habitat, leading to loss of suitable nesting and foraging sites and changes in prey abundance. Here we present the first report of successful nesting of the Little Eagle in greater Sydney (i.e. in the County of Cumberland), and recommend guidelines for management. The nest, discovered in a Smooth-barked Apple Angophora costata in the suburb of Ingleside on 15 October 2016, was visited one to three times per week, and observations on behaviour, diet and habitat of the Eagles were noted. The most common prey species taken was the European Rabbit Oryctolagus cuniculus . The chick fledged at c. 9 weeks old. The nest-site is at risk from a proposed development in the area and needs to be adaptively managed to ensure the continued presence and nesting of this species at this site.

Knowledge on how life history traits affect distribution in range-restricted and endemic plants is paramount for conservation and management, particularly for threatened species. Traits relating to dispersal ability are important in the ongoing persistence of range restricted species and may present a pathway to extinction or invasion. This is evident in the highly diverse and cosmopolitan genus Senecio (Asteraceae), where both threatened and invasive species occur within Australia. In this study, propagule geometry, settling velocity and dispersal potential for two range-restricted and threatened native taxa (S. linearifolious var. dangarensis Belcher ex I.Thomps., S. spathulatus var. attenuatus I.Thomps.) are contrasted with four native taxa that occupy wider ranges (S. amygdalifolius F.Muell., S. l. var. arachnoideus I.Thomps., S. l. var. macrodontus (DC.) I.Thomps., S. pinnatifolius A.Rich. var. pinnatifolius) and one introduced, wide-ranging species (S. madagascariensis Poir.). Differences were found in settling velocity and propagule morphology across all taxa. Based on propagule morphology, S. amygdalifolius has the greatest dispersal potential, S. spathulatus var. attenuatus the smallest, whereas all other taxa were similar. Although useful, dispersal potential alone does not fully explain distributional differences between all range-restricted and widespread taxa, and close assessment of habitat attributes may be required to further elucidate dispersal limitations in some taxa.

The Brown Goshawk Accipiter fasciatus has a variable diet comprising mainly avian prey and mammals, and most observations suggest that it employs a range of ambush tactics but rarely uses long-distance aerial pursuits. Here I document a rare instance of a successful long-distance aerial pursuit of an Australian Raven Corvus coronoides by a Brown Goshawk, on 29 March 2015, on Broughton Island, New South Wales. After multiple unsuccessful aerial attacks, the Goshawk eventually succeeded. Although corvids are abundant and widespread throughout Australia and are within the preferred avian prey size range, they are rarely observed in the Goshawk’s diet. Two ecological factors probably contributed to this observation: (1) there is little woodland here and thus little concealment for ambush tactics and (2) prey availability on Broughton Island and the surrounding islands has been altered by programs to eradicate pest mammals, thereby limiting the prey available to this species in this area.

We report on a new experimental method based on initial-state radiation (ISR) in e-p scattering, in which the radiative tail of the elastic e-p peak contains information on the proton charge form factor ($G_E^p$) at extremely small $Q^2$. The ISR technique was validated in a dedicated experiment using the spectrometers of the A1-Collaboration at the Mainz Microtron (MAMI). This provided first measurements of $G_E^p$ for $0.001\leq Q^2\leq 0.004 (GeV/c)^2$., Comment: 6 pages, 3 figures

The helicity-dependent recoil proton polarizations P_{x}^{'} and P_{z}^{'} as well as the helicity-independent component P_{y} have been measured in the p(e[over →],e^{'}p[over →])π^{0} reaction at four-momentum transfer Q^{2}≃0.1 GeV^{2}, center-of-mass proton emission angle θ_{p}^{*}≃90°, and invariant mass W≃1440 MeV. This first precise measurement of double-polarization observables in the energy domain of the Roper resonance P_{11}(1440) by exploiting recoil polarimetry has allowed for the extraction of its scalar electroexcitation amplitude at an unprecedentedly low value of Q^{2}, establishing a powerful instrument for probing the interplay of quark and meson degrees of freedom in the nucleon.

Rises in abundance of a population in response to increased resources is often followed by a rise in predator abundance. The non-threatened eastern barn owl (Tyto alba delicatula) and the threatened eastern grass owl (Tyto longimembris) are predators that may have occupancy patterns linked with prey abundance. It is important to identify the resources that cause increases in primary prey items to further understanding of the ecology of these species. Here I test the hypothesis that grass seeds cause increased abundances of wetland-dwelling house mice (Mus musculus) in austral summer, and identify a wetland monocot that provides a food recourse to achieve this effect, as well as report eastern grass owl and barn owl observations. A 2.6 ha wetland area (on Kooragang Island, New South Wales) was surveyed almost weekly to quantify abundance of prey items from September to April for three years (2016–2019). Typha sp. (a monocot) had flowering periods that coincided with increases in house mouse observations (n = 90 in flowering, n = 2 in non-flowering), where 22% were detected feeding on Typha flowers/seeds or fleeing from flower stalks. Eastern grass owls were only observed during a Typha flowering period (n = 3). These observations confirmed the original hypothesis and led to the formulation of another hypothesis: wetland occupancy by eastern grass owls is influenced by Typha flowering. Future studies should aim to test this hypothesis and identify other wetland plants that provide an important food source for wetland-dwelling rodents.

The chlorinated triarylphosphine P(C6H5)(2-C6H4Cl)2 (1) has been used as a supporting ligand in the Suzuki−Miyaura coupling of aryl boronic acids with aryl halides. Aryl bromides without ortho substituents were successfully coupled at room temperature, while reactions involving sterically hindered aryl bromides required slight heating (70 °C). Electron-deficient aryl chlorides were also successfully coupled with heating (90 °C). Key reaction parameters such as order of addition, choice of mineral base, solvent volume, temperature, 1/Pd ratio, as well as electronic and steric variation of the aryl halide have been investigated and are reported.

In an attempt to contribute further insight into the discrepancy between the Lamb shift and elastic scattering determinations of the proton charge radius, a new experiment at MAMI is underway, aimed at measuring proton form-factors at very low momentum transfers by using a new technique based on initial state radiation. This paper reports on the conclusions of the pilot measurement performed in 2010, whose main goal was to check the feasibility of the proposed experiment and to recognize and overcome any obstacles before running the full experiment. The modifications to the experimental apparatus are then explained which significantly improved the quality of data collected in the full scale experiment, which was successfully executed in August 2013. At the end first findings of the new experiment are discussed.

A massive, but light, Abelian U(1) gauge boson is a well-motivated possible signature of physics beyond the standard model of particle physics. In this Letter, the search for the signal of such a U(1) gauge boson in electron-positron pair production at the spectrometer setup of the A1 Collaboration at the Mainz Microtron is described. Exclusion limits in the mass range of 40 MeV/c^{2} to 300 MeV/c^{2}, with a sensitivity in the squared mixing parameter of as little as ε^{2}=8×10^{-7} are presented. A large fraction of the parameter space has been excluded where the discrepancy of the measured anomalous magnetic moment of the muon with theory might be explained by an additional U(1) gauge boson.

Electron scattering fixed target experiments are a versatile tool to explore various physics phenomena. Recently these experiments came into focus to search for $U(1)$ extensions of the Standard Model of particle physics at low energies. These extensions are motivated from anomalies in astrophysical observations as well as from deviations from Standard Model predictions, such as the discrepancy between the experimental and theoretical determination of the anomalous magnetic moment of the muon. They also arise naturally when the Standard Model is embedded into a more general theory. In the considered $U(1)$ extensions a new, light messenger particle $\gamma^\prime$, the hidden photon, couples to the hidden sector as well as to the electromagnetic current of the Standard Model by kinetic mixing, which allows for a search for this particle e.g. in the invariant mass distribution of the process $e (A,\,Z)\rightarrow e (A,\,Z) l^+ l^-$. In this process the hidden photon is emitted by bremsstrahlung and decays into a pair of Standard Model leptons. In this work we study the applicability of the Weizs\"acker-Williams approximation to calculate the signal cross section of the process, which is widely used to design such experimental setups. Furthermore, based on a previous work, we investigate the discovery potential of future experimental setups at the Jefferson Lab. For that purpose we simulate the relevant cross sections for the signal and the QED background in the actual kinematical setups and obtain projected exclusion limits., Comment: 16 pages, 12 figures

Motivated by anomalies in cosmic ray observations and by attempts to solve questions of the Standad Model of particle physics like the (g-2)_mu discrepancy, U(1) extensions of the Standard Model have been proposed in recent years. Such U(1) extensions allow for the interaction of Dark Matter by exchange of a photon-like massive force carrier \gamma' not included in the Standard Model. In order to search for \gamma' bosons various experimental programs have been started. One approach is the dedicated search at fixed-target experiments at modest energies as performed at MAMI or at the Jefferson Lab. In these experiments the process e(A,Z)->e(A,Z)l^+l^- is investigated and a search for a very narrow resonance in the invariant mass distribution of the l^+l^- pair is performed. In this work we analyze this process in terms of signal and background in order to describe existing data obtained by the A1 experiment at MAMI with the aim to give accurate predictions for exclusion limits in the \gamma' parameter space. We present a detailed theoretical analysis of the cross sections entering in the description of such processes., Comment: 18 pages, 12 figures

The A1 Collaboration at the Mainz Microtron (MAMI) operates high resolution spectrometers at very high luminosities for fixed target electron scattering experiments. The setup is well suited for the search for dark photons in the mass range between 50 MeV and 300 MeV. In these experiments, a possible dark photon would appear as a sharp peak in the mass spectrum of di-lepton electro-production. In this presentation the potential of the setup is presented and the possibilities for future experiments for dark photon searches at MAMI are discussed.

With anomalies found in cosmic ray observations and unsolved questions of the Standard Model of particle physics like the discrepancy in the muon's anomalous magnetic moment, the idea of an U(1) extension of the Standard Model arose. This extension allows for the interaction of Dark Matter by exchange of a photon-like massive force carrier $A'$ not included in the Standard Model. We discuss the possibility to constrain the dark photon parameter space by using data taken from rare kaon decays. Therefore we analyze the decay $K\rightarrow \mu \nu A'$ as a signal process and calculate the expected Standard Model background. Using these results we calculate new limits on the $A'$ parameter space, providing motivations for new rare kaon decay experiments to extend the existing $A'$ bounds., Comment: 5 pages, 4 figures

The relative importance of different sites of alkylation on DNA was determined by comparing two ethylating agents. 1-Ethyl-1-nitrosourea (ENU) ethylates DNA with a higher proportion of total adducts on ring oxygens than ethyl methanesulfonate, which ethylates with a higher proportion of total adducts on the N-7 of guanine. Research with somatic cells in culture and prokaryotes strongly suggests that O 6 -guanine (O 6 -G) is the principal genotoxic site. To determine the importance in germ-line mutagenesis of the O 6 -G site relative to the N-7 of guanine, dose-response curves were constructed for both ENU and EMS, where dose was measured as total adducts per deoxynucleotide (APdN) and response as sex-linked recessive lethals (SLRL) induced in Drosophila melanogaster spermatozoa. For both mutagens the dose response curve was linear and extrapolated to the origin. The dose-response curve for ENU was fit to an equation m = 6.2 D , and the dose response curve for EMS, from this and previous experiments, was m = 3.2 D where m = %SLRL and D = APdN x 10 −3 . Therefore, ENU is 1.9 times more efficient per adducts in inducing SLRL mutations than EMS. In vitro studies showed that ENU induced 9.5% of its total adducts on O 6 -G while EMS induced 2.0% of its adducts on O 6 -G. If O 6 -G was the sole genotoxic site, then ENU should be 4.8 times more efficient per adduct than EMS. In contrast, if N-7 G was the sole genotoxic site, ENU would be only 0.19 as effective as EMS. It was concluded that while O 6 -G was the principal genotoxic site, N-7 G made a significant contribution to germ-line mutagenesis.

To the Editor: Mahaffey et al1 and Granger et al2 studied pexelizumab (Alexion Pharmaceuticals, Inc, Cheshire, Conn) as adjunctive therapy to fibrinolysis1 and to primary percutaneous coronary intervention (PCI)2 in acute myocardial infarction. Both groups obtained unexpected results: Mahaffey et al1 did not observe any positive action of pexelizumab, and Granger et al2 did not obtain any reduction of infarct size but did observe a substantial decrease in mortality. It has been proposed that: (1) thrombolytics themselves are quick and powerful activators of complement3; (2) thrombolysis transforms grossly visible anemic infarcts into hemorrhagic ones4; (3) alleged erythrocytes in hemorrhagic infarcts are, in reality, cardiomyocyte apoptotic bodies4; and (4) activated complement plays a decisive role in their formation.4 Using PCI instead of thrombolysis, Granger et al2 not only avoided a powerful activation of complement and a transformation of anemic infarcts into …

The chlorinated triarylphosphine P(C6H5)(2-C6H4Cl)2 (1) has been used as a supporting ligand in the Suzuki−Miyaura coupling of aryl boronic acids with aryl halides. Aryl bromides without ortho substituents were successfully coupled at room temperature, while reactions involving sterically hindered aryl bromides required slight heating (70 °C). Electron-deficient aryl chlorides were also successfully coupled with heating (90 °C). Key reaction parameters such as order of addition, choice of mineral base, solvent volume, temperature, 1/Pd ratio, as well as electronic and steric variation of the aryl halide have been investigated and are reported.