Increased emission intensity can compensate for the presence of noise in human click-based echolocation

Echolocating bats adapt their emissions to succeed in noisy environments. In the present study we investigated if echolocating humans can detect a sound-refecting surface in the presence of noise and if intensity of echolocation emissions (i.e. clicks) changes in a systematic pattern. We tested people who were blind and had experience in echolocation, as well as blind and sighted people who had no experience in echolocation prior to the study. We used an echo-detection paradigm where participants listened to binaural recordings of echolocation sounds (i.e. they did not make their own click emissions), and where intensity of emissions and echoes changed adaptively based on participant performance (intensity of echoes was yoked to intensity of emissions). We found that emission intensity had to systematically increase to compensate for weaker echoes relative to background noise. In fact, emission intensity increased so that spectral power of echoes exceeded spectral power of noise by 12 dB in 4-kHz and 5-kHz frequency bands. The efects were the same across all participant groups, suggesting that this efect occurs independently of long-time experience with echolocation. Our fndings demonstrate for the frst time that people can echolocate in the presence of noise and suggest that one potential strategy to deal with noise is to increase emission intensity to maintain signal-to-noise ratio of certain spectral components of the echoes

The utilization of the phosphorus from an aluminium-iron rock phosphate. I. By the rat

The availability of the phosphorus in two samples of an aluminium-iron rock phosphate has been determined in the rat. In evaluating these products live weight gains, the ash content of the femurs and total phosphorus retention have been used as criteria. The rock phosphate was found to be a poor source of phosphorus.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

The availability of the calcium and phosphorus in " electrofos " for bone formation. I. In the rat

A basal diet, containing 0•06 per cent. calcium and 0•05 per cent. phosphorus, and albino rats, 4 to 5 weeks old and weighing approximately 60 grams, were used to ascertain the availability of electrofos I and electrofos II in comparison with dicalcium phosphate for bone formation. These phosphatic products, prepared by a thermal process, were studied at two levels giving diets containing 0•18 per cent. phosphorus and 0•36 per cent. phosphorus, the Ca : P ratio being maintained at about 2 : 1. Apart from live weight gains percentage retention of the relevant minerals as determined by slaughter tests and femur ash were used as criteria for evaluating the products. The averages of the results obtained are summarized in Table 18. It was found that both electrofos I and electrofos II were significantly less available for bone formation than calcium phosphate. However, more or less equal bone formation was obtained when these products were supplemented at about twice the level of calcium phosphate.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

The utilization of phosphorus from different sources by the rat

An experiment has been carried out in which the relative availability to young rats of the phosphorus in bone meal, bone ash, dicalcium phosphate and tricalcium phosphate has been ascertained. Live weight gains, the ash content of the femurs, and the total retention of phosphorus have been used as criteria in evaluating the supplements. Dicalcium phosphate was found superior to the other three supplements. Bone ash proved to be on a par with, if not better than bone meal. Tricalcium phosphate was least efficient as a source of phosphorus for bone formation. The practical significance of the observed differences in availability is briefly discussed.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

The utilization of the phosphorus from an aluminium-iron rock phosphate. II. By sheep

The availability of the phosphorus in "bone pellets" and aluminium-iron rock phosphates was compared with bone meal. In evaluating the products, inorganic phosphorus content of the blood, live weight gains, phosphorus retention, X-ray photographs and the pathological and chemical examination of the bones of the sheep were used as criteria. From the overall results thus obtained it can be concluded that: (i) "Bone pellets" are as efficient as bone meal as a source of phosphorus. (ii) Aluminium-iron rock phosphate is practically useless in this respect and cannot replace bone meal in animal nutrition.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

The effect of body stores and of method of supplementation on the efficiency of calcium and phosphorus utilization by sheep

(1) The Ca and P metabolism of two groups of young sheep, depleted of these minerals, was investigated in a series of three balance studies. (2) During the first 10 days on the bone meal supplemented ration, the inorganic P of the blood rose sharply from approximately 2•0 to 5•0 mgm. per 100 c.c. of blood, a level which was more or less maintained to the end of the experiment. (3) Under the conditions obtaining the method of bone meal supplementation had no influence on the efficiency of utilization of Ca and P. The implication of this for the problem of phosphate feeding under practical conditions is briefly discussed. (4) Ca and P utilization dropped considerably in the course of the 80 days on the enriched ration. Retention figures for Ca decreased from 22•5 to 12•7 per cent. and those for P from 53•1 to 32•2 per cent. (5) Due to the fact that no observations are available on the extent of replenishment during the period of bone meal feeding the final interpretations of these results must await the outcome of further investigations.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Tunneling spectra of submicron Bi2_2Sr2_2CaCu2_2O8+δ_{8+\delta} intrinsic Josephson junctions: evolution from superconducting gap to pseudogap

Tunneling spectra of near optimally doped, submicron Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ intrinsic Josephson junctions are presented, and examined in the region where the superconducting gap evolves into pseudogap. The spectra are analyzed using a self-energy model, proposed by Norman {\it et al.}, in which both quasiparticle scattering rate $\Gamma$ and pair decay rate $\Gamma_{\Delta}$ are considered. The density of states derived from the model has the familiar Dynes' form with a simple replacement of $\Gamma$ by $\gamma_+$ = ($\Gamma$ + $\Gamma_{\Delta}$)/2. The $\gamma_+$ parameter obtained from fitting the experimental spectra shows a roughly linear temperature dependence, which puts a strong constraint on the relation between $\Gamma$ and $\Gamma_{\Delta}$. We discuss and compare the Fermi arc behavior in the pseudogap phase from the tunneling and angle-resolved photoemission spectroscopy experiments. Our results indicate an excellent agreement between the two experiments, which is in favor of the precursor pairing view of the pseudogap.Comment: 7 pages, 6 figure

Origin of strange metallic phase in cuprate superconductors

The origin of strange metallic phase is shown to exist due to these two conditions---(i) the electrons are strongly interacting such that there are no band and Mott-Hubbard gaps, and (ii) the electronic energy levels are crossed in such a way that there is an electronic energy gap between two energy levels associated to two different wave functions. The theory is also exploited to explain (i) the upward- and downward-shifts in the $T$-linear resistivity curves, and (ii) the spectral weight transfer observed in the soft X-ray absorption spectroscopic measurements of the La-Sr-Cu-O Mott insulator.Comment: To be published in J. Supercond. Nov. Mag

Offspring physiology following the use of IVM, IVF and ICSI: a systematic review and meta-analysis of animal studies

OnlinePublBackground: Since the birth of the first baby using IVF technology in 1978, over 10 million children have been conceived via ART. Although most aspects of ARTs were developed in animal models, the introduction of these technologies into clinical practice was performed without comprehensive assessment of their long-term safety. The monitoring of these technologies over time has revealed differences in the physiology of babies produced using ARTs, yet due to the pathology of those presenting for treatment, it is challenging to separate the cause of infertility from the effect of treatments offered. The use of systematic review and meta-analysis to investigate the impacts of the predominant ART interventions used clinically in human populations on animals produced in healthy fertile populations offers an alternative approach to understanding the long-term safety of reproductive technologies. Objective and Rationale: This systematic review and meta-analysis aimed to examine the evidence available from animal studies on physiological outcomes in the offspring conceived after IVF, IVM or ICSI, compared to in vivo fertilization, and to provide an overview on the landscape of research in this area. Search Methods: PubMed, Embase and Commonwealth Agricultural Bureaux (CAB) Abstracts were searched for relevant studies published until 27 August 2021. Search terms relating to assisted reproductive technology, postnatal outcomes and mammalian animal models were used. Studies that compared postnatal outcomes between in vitro-conceived (IVF, ICSI or IVM) and in vivo-conceived mammalian animal models were included. In vivo conception included mating, artificial insemination, or either of these followed by embryo transfer to a recipient animal with or without in vitro culture. Outcomes included birth weight, gestation length, cardiovascular, metabolic and behavioural characteristics and lifespan. Outcomes: A total of 61 studies in five different species (bovine, equine, murine, ovine and non-human primate) met the inclusion criteria. The bovine model was the most frequently used in IVM studies (32/40), while the murine model was mostly used in IVF (17/20) and ICSI (6/8) investigations. Despite considerable heterogeneity, these studies suggest that the use of IVF or maturation results in offspring with higher birthweights and a longer length of gestation, with most of this evidence coming from studies in cattle. These techniques may also impair glucose and lipid metabolism in male mice. The findings on cardiovascular outcomes and behaviour outcomes were inconsistent across studies. Wider Implications: Conception via in vitro or in vivo means appears to have an influence on measurable outcomes of offspring physiology, manifesting differently across the species studied. Importantly, it can be noted that these measurable differences are noticeable in healthy, fertile animal populations. Thus, common ART interventions may have long-term consequences for those conceived through these techniques, regardless of the pathology underpinning diagnosed infertility. However, due to heterogeneous methods, results and measured outcomes, highlighted in this review, it is difficult to draw firm conclusions. Optimizing animal and human studies that investigate the safety of new reproductive technologies will provide insight into safeguarding the introduction of novel interventions into the clinical setting. Cautiously prescribing the use of ARTs clinically may also be considered to reduce the chance of promoting adverse outcomes in children conceived before long-term safety is confidently documented.Kiri H. Beilby, Ezra Kneebone, Tessa J. Roseboom, Indah M. van Marrewijk, Jeremy G. Thompson, Robert J. Norman, Rebecca L. Robker, Ben Willem J. Mol, and Rui Wan

Carrier relaxation, pseudogap, and superconducting gap in high-Tc cuprates: A Raman scattering study

We describe results of electronic Raman-scattering experiments in differently doped single crystals of Y-123 and Bi-2212. The comparison of AF insulating and metallic samples suggests that at least the low-energy part of the spectra originates predominantly from excitations of free carriers. We therefore propose an analysis of the data in terms of a memory function approach. Dynamical scattering rates and mass-enhancement factors for the carriers are obtained. In B2g symmetry the Raman data compare well to the results obtained from ordinary and optical transport. For underdoped materials the dc scattering rates in B1g symmetry become temperature independent and considerably larger than in B2g symmetry. This increasing anisotropy is accompanied by a loss of spectral weight in B2g symmetry in the range between the superconducting transition at Tc and a characteristic temperature T* of order room temperature which compares well with the pseudogap temperature found in other experiments. The energy range affected by the pseudogap is doping and temperature independent. The integrated spectral loss is approximately 25% in underdoped samples and becomes much weaker towards higher carrier concentration. In underdoped samples, superconductivity related features in the spectra can be observed only in B2g symmetry. The peak frequencies scale with Tc. We do not find a direct relation between the pseudogap and the superconducting gap.Comment: RevTeX, 21 pages, 24 gif figures. For PostScript with embedded eps figures, see http://www.wmi.badw-muenchen.de/~opel/k2.htm