Cognitive phenotype and differential gene expression in a hippocampal homologue in two species of frog

The complexity of an animal's interaction with its physical and/or social environment is thought to be associated with behavioral flexibility and cognitive phenotype, though we know little about this relationship in amphibians. We examined differences in cognitive phenotype in two species of frog with divergent natural histories. The greenand- black poison frog (Dendrobates auratus) is diurnal, displays enduring social interactions, and uses spatially distributed resources during parental care. Tungara frogs (Physalaemus=Engystomops pustulosus) are nocturnal, express only fleeting social interactions, and use ephemeral puddles to breed in a lek-type mating system. Comparing performance in identical discrimination tasks, we find that D. auratus made fewer errors when learning and displayed greater behavioral flexibility in reversal learning tasks than tungara frogs. Further, tungara frogs preferred to learn beacons that can be used in direct guidance whereas D. auratus preferred position cues that could be used to spatially orient relative to the goal. Behavioral flexibility and spatial cognition are associated with hippocampal function in mammals. Accordingly, we examined differential gene expression in the medial pallium, the amphibian homolog of the hippocampus. Our preliminary data indicate that genes related to learning and memory, synaptic plasticity, and neurogenesis were upregulated in D. auratus, while genes related to apoptosis were upregulated in tungara frogs, suggesting that these cellular processes could contribute to the differences in behavioral flexibility and spatial learning we observed between poison frogs and tungara frogs

REACHing for divergence?—UK chemical regulation post‐Brexit

On 1 January 2021, the United Kingdom formally exited the European Union (EU; Brexit) and ceased to be subject to EU chemical regulation requirements. Before Brexit, UK chemical policy was regulated largely by the EU. With its large internal market, sophisticated regulatory capability, and stringent regulatory framework, the EU has become the world's leading regulatory state, regularly influencing global industrial decisions and practices. At the time of writing, there has been limited academic analysis of the implications of Brexit for UK chemical regulation. More than two years post-Brexit, we have the opportunity to assess UK chemical regulation and revisit early expectations about regulatory divergence. This article takes the EU's Regulation on the Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) as a case study to analyze patterns of post-Brexit regulatory divergence, thereby providing one of the first analyses of the implications of Brexit on UK chemical regulation. Through the analysis and review of key documents and reports (n = 99), this article assesses the extent to which UK and EU regulatory (REACH) regimes are beginning to diverge and discusses the potential implications of any divergence for the United Kingdom. We find that the UK and EU chemical regulatory regimes are now evolving independently and provide clear, empirical evidence of an emerging divergence in regulatory decisions, ambitions, and approaches. The evidence suggests that the United Kingdom is currently unable to keep pace with EU developments, lacking the capacity, expertise, and capability of its EU counterparts, raising the prospect of further divergence in the future. Integr Environ Assess Manag 2024;00:1–10. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC)

Assessing negative cognitive style: Development and validation of a short-form version of the Cognitive Style Questionnaire

The Cognitive Style Questionnaire (CSQ) is a frequently employed measure of negative cognitive style, associated with vulnerability to anxiety and depression. However, the CSQ’s length can limit its utility in research. We describe the development of a Short-Form version of the CSQ. After evaluation and modification of two pilot versions, the 8-item CSQ Short Form (CSQ-SF) was administered to a convenience sample of adults (N = 278). The CSQ-SF was found to have satisfactory internal reliability and test–retest reliability. It also exhibited construct validity by demonstrating predicted correlations with measures of depression and anxiety. Results suggest that the CSQ-SF is suitable for administration via the Internet

On the derivative of the associated Legendre function of the first kind of integer order with respect to its degree

In our recent works [R. Szmytkowski, J. Phys. A 39 (2006) 15147; corrigendum: 40 (2007) 7819; addendum: 40 (2007) 14887], we have investigated the derivative of the Legendre function of the first kind, $P_{\nu}(z)$, with respect to its degree $\nu$. In the present work, we extend these studies and construct several representations of the derivative of the associated Legendre function of the first kind, $P_{\nu}^{\pm m}(z)$, with respect to the degree $\nu$, for $m\in\mathbb{N}$. At first, we establish several contour-integral representations of $\partial P_{\nu}^{\pm m}(z)/\partial\nu$. They are then used to derive Rodrigues-type formulas for $[\partial P_{\nu}^{\pm m}(z)/\partial\nu]_{\nu=n}$ with $n\in\mathbb{N}$. Next, some closed-form expressions for $[\partial P_{\nu}^{\pm m}(z)/\partial\nu]_{\nu=n}$ are obtained. These results are applied to find several representations, both explicit and of the Rodrigues type, for the associated Legendre function of the second kind of integer degree and order, $Q_{n}^{\pm m}(z)$; the explicit representations are suitable for use for numerical purposes in various regions of the complex $z$-plane. Finally, the derivatives $[\partial^{2}P_{\nu}^{m}(z)/\partial\nu^{2}]_{\nu=n}$, $[\partial Q_{\nu}^{m}(z)/\partial\nu]_{\nu=n}$ and $[\partial Q_{\nu}^{m}(z)/\partial\nu]_{\nu=-n-1}$, all with $m>n$, are evaluated in terms of $[\partial P_{\nu}^{-m}(\pm z)/\partial\nu]_{\nu=n}$.Comment: LateX, 40 pages, 1 figure, extensive referencin

Confinement of Spin and Charge in High-Temperature Superconductors

By exploiting the internal gauge-invariance intrinsic to a spin-charge separated electron, we show that such degrees of freedom must be confined in two-dimensional superconductors experiencing strong inter-electron repulsion. We also demonstrate that incipient confinement in the normal state can prevent chiral spin-fluctuations from destroying the cross-over between strange and psuedo-gap regimes in under-doped high-temperature superconductors. Last, we suggest that the negative Hall anomaly observed in these materials is connected with this confinement effect.Comment: 12 pages, 1 postscript figure, to appear in PRB (RC), May 199

MGMT Promoter Methylation Cutoff with Safety Margin for Selecting Glioblastoma Patients into Trials Omitting Temozolomide: A Pooled Analysis of Four Clinical Trials.

The methylation status of the O <sup>6</sup> -methylguanine DNA methyltransferase (MGMT) gene promoter is predictive for benefit from temozolomide in glioblastoma (GBM). A clinically optimized cutoff was sought allowing patient selection for therapy without temozolomide, while avoiding to withhold it from patients who may potentially benefit.Experimental Design: Quantitative MGMT methylation-specific PCR data were obtained for newly diagnosed patients with GBM screened or treated with standard radiotherapy and temozolomide in four randomized trials. The pooled dataset was randomly split into a training and test dataset. The unsupervised cutoff was obtained at a 50% probability to be (un)methylated. ROC analysis identified an optimal cutoff supervised by overall survival (OS). For 4,041 patients valid MGMT results were obtained, whereof 1,725 were randomized. The unsupervised cutoff in the training dataset was 1.27 (log <sub>2</sub> [1,000 × (MGMT+1)/ACTB]), separating unmethylated and methylated patients. The optimal supervised cutoff for unmethylated patients was -0.28 (AUC = 0.61), classifying "truly unmethylated" (≤-0.28) and "gray zone" patients (>-0.28, ≤1.27), the latter comprising approximately 10% of cases. In contrast, for patients with MGMT methylation (>1.27) more methylation was not related to better outcome. Both methylated and gray zone patients performed significantly better for OS than truly unmethylated patients [HR = 0.35, 95% confidence interval (CI), 0.27-0.45, P < 0.0001; HR = 0.58, 95% CI, 0.43-0.78, P < 0.001], validated in the test dataset. The MGMT assay was highly reproducible upon retesting of 218 paired samples (R <sup>2</sup> = 0.94). Low MGMT methylation (gray zone) may confer some sensitivity to temozolomide treatment, hence the lower safety margin should be considered for selecting patients with unmethylated GBM into trials omitting temozolomide

Physical Optimization of Quantum Error Correction Circuits

Quantum error correcting codes have been developed to protect a quantum computer from decoherence due to a noisy environment. In this paper, we present two methods for optimizing the physical implementation of such error correction schemes. First, we discuss an optimal quantum circuit implementation of the smallest error-correcting code (the three bit code). Quantum circuits are physically implemented by serial pulses, i.e. by switching on and off external parameters in the Hamiltonian one after another. In contrast to this, we introduce a new parallel switching method that allows faster gate operation by switching all external parameters simultaneously. These two methods are applied to electron spins in coupled quantum dots subject to a Heisenberg coupling H=J(t) S_1*S_2 which can generate the universal quantum gate `square-root-of-swap'. Using parallel pulses, the encoding for three-bit quantum error correction in a Heisenberg system can be accelerated by a factor of about two. We point out that parallel switching has potential applications for arbitrary quantum computer architectures.Comment: 13 pages, 6 figure

Benthic marine calcifiers coexist with CaCO3-undersaturated seawater worldwide

Ocean acidification and decreasing seawater saturation state with respect to calcium carbonate (CaCO3) minerals have raised concerns about the consequences to marine organisms, especially those building structures made of CaCO3. A large proportion of benthic marine calcifiers incorporate Mg2+ into their calcareous structures (i.e., Mg-calcite) which, in general, reduces mineral stability. The vulnerability of some marine calcifiers to ocean acidification is related to the solubility of their calcareous structures, but not all marine organisms conform to this because of sophisticated biological and physiological mechanisms to construct and maintain CaCO3 structures. Few studies have considered seawater saturation state with respect to species-specific mineralogy in evaluating the effect of ocean acidification on marine organisms. Here, a global dataset of skeletal mol % MgCO3 of benthic calcifiers and in situ environmental conditions (temperature, salinity, pressure, and [CO32-]) spanning a depth range of 0 m (subtidal/neritic) to 5500 m (abyssal) was assembled to calculate in situ seawater saturation states with respect to species-specific Mg-calcite mineral compositions (?Mg-x). Up to 20% of all studied calcifiers at depths 1200 m currently experience seawater mineral undersaturation with respect to their skeletal mineral phase (?Mg-x1200 m) of all studied calcifying species to seawater undersaturation. These observations underscore concerns over the ability of marine benthic calcifiers to continue to construct and maintain their calcareous structures under these conditions. We advocate that ocean acidification tipping points can only be understood by assessing species-specific responses, and because of different seawater ?Mg-x present in all marine ecosystems