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B chromosomes are intriguing "selfish" genetic elements, many of which exhibit higher-than-Mendelian transmission. This perspective highlights a group of B chromosomes known as Paternal Sex Ratio chromosomes (PSRs), which are found in several insects with haplo-diploid reproduction. PSRs harshly alter the organism's reproduction to facilitate their own inheritance. A manifestation of this effect is the conversion of female destined individuals into males. Key to this conversion is the mysterious ability of PSRs to cause elimination of the sperm-inherited half of the genome during zygote formation. Here we discuss how PSRs were discovered, what is known about how they alter paternal chromatin dynamics to cause sex conversion, and how PSR-induced genome elimination is different from other forms of programmed genome elimination in different insects. PSRs also stand out because their DNA sequence compositions differ in remarkable ways from their insect's essential chromosomes, a characteristic suggestive of interspecies origins. Broadly, we also highlight poorly understood aspects of PSR dynamics that need to be investigated. [ABSTRACT FROM AUTHOR]

The permanently shadowed regions (PSRs) at the lunar poles without direct solar illumination maintain low temperatures throughout the year, making them optimal environments for the preservation of water ice. This paper investigates the diurnal and seasonal temperature variations of the PSRs within craters at the lunar south pole. The craters de Gerlache, Shoemaker, Amundsen, and Wiechert E are selected to explore how latitudes and shapes impact PSR temperature. Using the ray tracing approach, the shadow effect of terrain on the scattered sunlight and thermal radiation is calculated. PSR temperatures are simulated with the one-dimensional heat conduction equation. The thermal emissivity of the lunar surface is studied. Simulations with anisotropic emissivity are closer to the Diviner data in PSRs than the simulations with isotropic emissivity. In addition, by comparing the simulations to the Diviner data, it is found that the thermal conductivity at the extremely low temperatures in PSRs might be lower than that at high temperatures outside the PSRs. Simulations of the selected craters are used to study the influence of polar day phenomena occurring at high-latitude craters during the summer and the effect of direct solar illumination at the floors of low-latitude craters on the temperature distribution of PSRs. The influence of crater shape is analyzed as well by investigating the temperature distributions within PSRs of flat-floored and bowl-shaped craters. With the analysis of the heat flux propagation distances, emission angles, and incident angles, this study quantitatively elucidates the spatial and temporal variations in PSR temperatures. To explain why the Diviner data are lower than the simulation results at the solar-illuminated crater walls, an undulating rough surface is generated. The locations of the Sun and the observer on opposite sides of the rough surface may decrease the observed infrared brightness temperature according to the simulations. The PSR peak temperatures simulated with the anisotropic emissivity and thermal conductivity for PSRs are used to search for low-temperature areas suitable for preserving water ice within de Gerlache and Shoemaker. • Model for spatial and temporal temperature variations in the permanently shadowed regions on the Moon. • The thermal emissivity of rough lunar surface is probably anisotropic. • Impact of Polar day phenomena occurring at high-latitude craters during the summer. • Different temperature distributions of bowl-shaped and flat-floored craters. • Explanation of the differences between Diviner data and simulations by a rough-surface model. [ABSTRACT FROM AUTHOR]

Highlight • Development of a new 2D-FRS code. • Gaussian approximation is used to analyze performance analysis of 2D-FRS system. • Simulation validation of 2D-FRS numerical model. • Power saving feature at 2D-FRS receiver. • Accommodation of large number of active users with high bit rate. Abstract In this paper a new algorithm to generate two dimensional fixed right shifting (2D-FRS) code sequences is proposed, which is based on spectral/spatial incoherent OCDMA system. The proposed 2D-FRS algorithm is designed using 1D-FRS code with minimum cross correlation (MCC). The 2D-FRS codes enhance the system cardinality and offer elimination capability of MCC and its associated phase induced intensity noise (PIIN). Furthermore, the proposed algorithm allows multiple users with different code sequences to transmit data with minimum likelihood of interference. The architecture of transmitter-receiver structure of spectral/spatial 2D-FRS OCDMA system is presented. Gaussian approximation is used to analyze performance of the proposed 2D-FRS OCDMA system by investigating noise sources at photodiodes (PDs). It is shown that PD-1 and PD-3 have lower contribution in terms of noise power as compared to PD-0 and PD-2 due to division operation in MCC elimination process at the balanced detectors. Simulation results also validates the proposed system for an agreeable bit error rate (BER) of 10−9. It is observed that the 2-D FRS OCDMA system can support a higher number of users in deterministic and stochastic methods compared to the reported techniques such as Diagonal Eigenvalue Unity (DEU) and Two-Dimensional Diluted Perfect Difference codes (2D-DPD codes). The 2D-FRS cardinality surpassing the 2D-DPD and 2D-DEU by ≈71.21% and ≈9.09% respectively at the BER of 10−9. At 622 Mbits/s transmission data rate, the 2-D FRS meets the optical transmission requirements with lowest effective transmitted source power (P sr), −27.5 dBm in comparison to published codes. [ABSTRACT FROM AUTHOR]

PM 2.5 concentration have received considerable attention from meteorologists, who are able to notify the public and take precautionary measures to prevent negative effects on health. Therefore, establishing an efficient early warning system plays a critical role in fostering public health in heavily polluted areas. In this study, ensemble empirical mode decomposition and least square support vector machine (EEMD-LSSVM) based on Phase space reconstruction (PSR) is proposed for day-ahead PM 2.5 concentration prediction, according to the application of a decomposition-ensemble learning paradigm. The main methods of the proposed model mainly include: first, EEMD is presented to decompose the original data of PM 2.5 concentration into some intrinsic model functions (IMFs); second, PSR is applied to determine the input form of each extracted component; third, LSSVM, an effective forecasting tool, is used to predict all reconstructed components independently; finally, another LSSVM is employed to aggregate all predicted components into ensemble results for the final prediction. The empirical results show that this proposed model can outperform the comparison models and can significantly improve the prediction performance in terms of higher predictive and directional accuracy. [ABSTRACT FROM AUTHOR]

Radar observations made by the Arecibo Observatory have revealed radar-bright deposits in the north polar region of Mercury which are consistent with water ice. These deposits are generally associated with floors of deep craters in permanent shadow. In this paper, we revisit topographic data, illumination, and associated thermal conditions of the north polar region of Mercury to investigate these radar-bright deposits. We used Mercury Laser Altimeter (MLA) data from the MESSENGER mission to derive a dedicated, adjusted high-resolution Digital Terrain Model (DTM) of the north polar region at 250 m/pixel. Based on this DTM, illumination conditions and temperature were derived for the first time on the fully available MLA dataset. Generally, craters equatorward of 86 ∘ N are found to be too hot to contain surface water ice due to effective self-heating. For those warm craters that do contain radar-bright deposits, temperatures within the upper 10–20 cm of regolith are cold enough for water ice to be stable. Using our improved DTM, we confirm previously MLA-modeled illumination conditions in Prokofiev crater and argue that radar-bright patches outside the PSR in the area may be explained by icy deposits in cold and shallow (within 5 cm) sub-surface layers. In the radar observations we find a strong, unphysical correlation between radar-bright pixels and the number of radar observations per pixel. Consequently, several PSRs which were classified as free of radar-bright material (mainly at longitudes 120–340 ∘ E) are most likely subject to a bias in the averaging process in deriving the composite radar image and might contain water ice after all. • Craters at a distance greater than 4 ∘ from the pole are found to be too hot to contain surface water ice due to effective self-heating. • The radar-bright area within Prokofiev crater that is not associated with a PSR can be explained by cold temperatures in the shallow sub-surface. • Radar data is demonstrated to suffer from an observation bias; PSRs previously considered to be devoid of radar-bright material might contain water ice. [ABSTRACT FROM AUTHOR]

The developed polymerase spiral reaction-based technique specifically amplified the ceuE gene of C. coli and involved a three-step centrifugation method for DNA extraction. PSR, real-time and end-point PCR were able to detect 62 fg, 620 fg and 6.2 pg C. coli DNA/tube, respectively. PSR detection limits for artificially contaminated pork samples without enrichment, with 12 h enrichment and after 24 h enrichment were 1000 CFU/g, 100 CFU/g, and 10 CFU/g samples, respectively which were ten times better than real-time PCR. The detection performance of PSR (with 12 h enrichment) was also compared to culture (ISO10272-1:2017) method using 75 naturally-contaminated samples, which revealed the sensitivity, specificity, PPV, NPV and accuracy of 100% (95%CI, 73.2%–100%), 98.4% (95%CI, 90%–99.9%), 93.3% (95%CI, 66%–99.6%), 100% (95%CI, 92.5%–100%) and 98.7% (95%CI, 92.8%–99.9%), respectively. The advantage and novelty of this assay are its equipment-free nature, dye-based interpretation by the naked eye, and the requirement of one enzyme and one primer pair. This assay could be a better alternative to other molecular methods and may help in reducing the possible troubles (e.g., gastroenteritis, hospitalization, or death) of belated detection of C. coli in food products. This is the primary report applying the PSR for C. coli detection. [Display omitted] • PSR assay was developed to detect Campylobacter coli for the first time. • The assay involved simple 3-step centrifugation based DNA extraction method. • The assay involved pre-addition of HNB dye for result interpretation. • Analytical sensitivity and detection limit was 62 fg DNA/tube and 100 CFU/g pork. • The assay is equipment-free and requires single enzyme and a primer pair. [ABSTRACT FROM AUTHOR]

Abstract: Cooking installations are among the most abundant features in Bronze and Iron Age archaeological sites in the southern Levant, yet until now their study has been mostly descriptive. We present a study of 11 purported archaeological cooking installations from three different Bronze and Iron Age sites in Israel in which we deployed a variety of microarchaeological techniques. We provide direct physical evidence, based on Fourier Transform Infrared (FTIR) spectroscopy demonstrating that the archaeological installations were operated with temperatures as high as 900 °C. Using this technique we also demonstrate that all the mud-constructed installations studied by us were internally-fueled and therefore should be identified as Tannurs rather than the externally- fueled Tabuns. We studied in detail the quantities of ash-related microscopic remains, including opaline phytoliths, calcitic wood ash pseudomorphs and dung spherulites. We show that phytolith morphotype analysis cannot distinguish between wood-dominated and dung-dominated fuel materials, while a newly developed method that calculates the ratio of ash pseudomorphs to dung spherulites (PSR method) makes such a distinction possible. Moreover, we experimented with the effect of partial dissolution on fuel ash PSR values and utilize the results to explain taphonomy and diagenesis associated with two types of archaeological cooking installations – pebble hearths and baking ovens. In addition, we identified micromorphological criteria that can be used to assess whether ash deposits in or above a cooking installations are in situ and/or disturbed. Taken together, all lines of evidence used in this study indicate that wood was the major fuel material across time and space in the studied archaeological contexts, while dung was a secondary source of fuel. This observation also cross-cuts different culture-historical entities (Philistines, Canaanites, Israelites and Egyptians). In addition, wood was preferred as fuel irrespective of environmental differences among the studied sites. This study is yet another demonstration of the value of integrating microarchaeological techniques and approaches to traditional macroscopic archaeology. [Copyright &y& Elsevier]

Abstract: Mud constructed cooking installations such as ovens and hearths are common in modern, pre-modern and archaeological domestic contexts in West and Central Asia. Archaeological cooking installations are primarily identified using analogy of shape and size to ethnographic installations. The study presented here establishes direct evidence to the use of fire within mud constructed cooking installations, thus providing means for reducing ambiguity in identification of archaeological cooking installations. In addition, we present here a newly developed method that enables a clear-cut distinction between wood and dung ashes used as fuel materials in many modern and archaeological domestic contexts. The study is based on an ethnoarchaeological research in rural households at the Republic of Uzbekistan that was followed by geoarchaeological analyses of installation walls, wood ash, dung ash and wood and dung standards collected in the study area. Field work included ethnographic observations, interviews with informants and temperature measurements during cooking experiments. We show that changes in the clay mineral structure due to exposure to high temperatures on the interior walls of cooking installations can be detected using FTIR (Fourier Transform Infrared) spectroscopy, providing for the first time direct evidence to the use of fire within such installations. We demonstrate that the temperature recorded by clay alteration on installation walls as well as in the ashes left on installation bottoms does not correspond to baking or cooking temperatures. We also show that the newly developed method, based on the ratio of wood ash pseudomorphs to dung spherulites, separates between wood and dung ashes with very high certainty. Yet, we identify a range of values where differentiation between wood and dung ashes is uncertain, and suggest it results from intensive mixing processes. Lastly, we show that phytolith morphotype analysis is an insufficient tool, if used alone, for distinguishing wood from dung ashes in the study area. The newly developed tools for temperature estimation within mud constructed installations and for fuel origin determination contribute to better understanding of cooking-related practices, and can be applied to archaeological contexts worldwide. [Copyright &y& Elsevier]

The interaction between phosphatidylserine and its receptor on phagocytic cells plays a critical role in the clearance of apoptotic bodies under normal physiological condition. A specific receptor for phosphatidylserine (PSR) has recently been identified by phage display and shown to mediate phosphatidylserine dependent phagocytosis. Here we show that the protein encoded by the PSR cDNA is localized in the nuclei through multiple nuclear localization signals. First, a fusion between PSR and GFP is localized in the nuclei of transfected cells, suggesting that PSR have intrinsic nuclear localization capability. Indeed, affinity-purified anti-PSR antibodies identified a 47 kDa protein species in cells transfected with untagged PSR and localized this protein in the nuclei by immunofluorescent confocal microscopy. In NIH3T3 cells, which express endogenous PSR mRNA, a similar 47 kDa species was detected and localized in the nuclei. Finally, multiple nuclear localization signals were identified in PSR sequence, each capable of targeting GFP to the nuclei. Together, these results suggest that PSR may serve a dual role both on the cell surface and in the nuclei. [Copyright &y& Elsevier]

Staphylococcus aureus is one of the most common and leading causes of food poisoning and also responsible for multifarious diseases in humans. Rapid and on-site detection of S. aureus is of specific importance in developing countries. In the present study, a polymerase spiral reaction (PSR) assay was developed for sensitive, rapid and visual detection of S. aureus and validated in meat using pork as a model. The specificity of the PSR assay was ascertained by using 18 S. aureus and 17 non- S.aureus strains. The PSR assay was 100- and 10-fold more sensitive than conventional end-point PCR and real-time PCR, respectively. The limit of detection of the PSR assay was 19.9 × 103 CFU/g of pork without enrichment and 19.9 CFU/g after 6 h enrichment. The detection of 19.9 CFU/g of pork was attained within 8 h. Real-world or field applicability of the developed assay was evaluated by screening 76 raw and processed pork samples. Seeing its rapidity, simplicity, cost-effectiveness, user-friendliness and sophisticated-equipment free nature, this assay has the prospective to turn into the assay of choice for regular detection of S. aureus in foods in less-advanced laboratories. To our knowledge, this is the first report to use PSR for the detection of S. aureus. • A novel PSR assay was developed for rapid and visual detection of Staphylococcus aureus in meat. • The analytical sensitivity of the PSR assay was 100 and 10 fold more than the conventional and real-time PCR, respectively. • The detection of limit of 19.9 × 103 CFU and 19.9 CFU per gram of meat was attained within 2 h and 8 h, respectively. [ABSTRACT FROM AUTHOR]

• Development of new SSM families. • A configurable transmitter–receiver structure using S S M SSM code to support QoS. • High and Low QoS diversity are offered based on user choices. • Accommodation of large number of active users with high bit rate. This paper proposes a new coding scheme for spectral amplitude coding (SAC) family, known as Sigma Shift Matrix (SSM). Two techniques are proposed for the design of SSM coding scheme. The first technique combines the identity and upper shift matrices to form an SSM coding matrix named as SSM I. The second approach adapts the assembly of a single – entry, lower and upper shift matrices to compose another SSM matrix called SSM s. Combination of these matrices generates variable SSM code families, which can provide more flexibility in code weight selection and the number of users respectively. Furthermore, a modified SSM (MSSM) coding scheme is proposed through bitwise ANDing of SSM I and SSM S to further elevate performance of the proposed setup. The optimized structure of SSM coding scheme eliminates the influence of multiple access interference (MAI) and alleviate the effect of phase induced intensity noise (PIIN). Numerical results show that MSSM, SSM I and S S M S SSM S outperform the existing coding schemes in descending order and proves to be an efficient candidate for the implementation of high capacity next generation of optical communication networks. [ABSTRACT FROM AUTHOR]