The Consistency of Moving Twins Measurements in Spatially Closed Universe

المفارقة التوأم العادية هي مشكلة شيخوخة المراقبين التوأمين  A و B، B يسافر بسرعة النسبية ويعود مرة أخرى إلى A حيث A في حالة سكون. وفقاً لحساب كلا التوامين، إذا كان كل واحد يعتبر نفسه في حالة سكون، فسيكون الآخر أصغر سناً في نهاية الرحلة. وهذا الأمر المتناقض، في الواقع تظهر المفارقة بسبب تعجيل التوأم المتنقل (B) ولذلك يصبح B أصغر سناً في نقطة العودة. تم حل هذه المفارقة حسب T. Dray عن طريق إجراء الحساب في كون أسطواني مغلق، حيث مشكلة التعجيل يتم حلها للتوأم المسافر هذا يعني أن التوأم المسافر (أسرع) سيكون أصغر سناً بغض النظر عن التوأم الذي أجرى الحساب. حسب حساباتنا الحالية، أظهرنا ما إذا كان كلا التوأمين يسافران بسرعة نسبية في كون اسطواني مغلق و التوأم الأسرع (B) اجرى الحسابات. ستظهر النتيجة دائماً أن توأم الاسرع سيكون له وقت أقل. هذه النتيجة تنسق مع نتيجة T. Dray ، عندما يكون احد التوأمين في حالة سكون والآخر يتحرك.The ordinary twin paradox is a problem of ageing of two twin observers A and B, B travels with a relativistic speed and returns back to A where A is at rest. According to each twin's calculation, if each considers itself at rest, the other would be younger at the end of the trip. This is paradoxical, in fact the paradox appears due to the accelerating of the travelling twin (B) and so that B will be younger at the return point. This paradox has been resolved by T. Dray by doing the calculation in a closed cylindrical universe, were the acceleration problem has been resolved for the travelling twin. This means that the travelling (faster) twin will be younger no matter which twin performed the calculation. In the present calculation we have shown if both twins are travelling with a relativistic speed in such universe and the faster twin (B) made the calculations. The result will always shows that the faster twin will have less proper time. This result is consistent with that of T. Dray, when one twin is at rest and other is moving

Individuals lack the ability to accurately detect emotional piloerection

Piloerection (e.g., goosebumps) is an essential thermoregulatory and social signaling mechanism in non‐human animals. Although humans also experience piloerection—often being perceived as an indicator of profound emotional experiences—its comparatively less effective role in thermoregulation and communication might influence our capacity to monitor its occurrence. We present three studies (total N = 617) demonstrating participants' general inability to detect their own piloerection events and their lack of awareness that piloerection occurs with a similar frequency on multiple anatomical locations. Self‐reported goosebumps were more frequent than observed piloerection. However, only 31.8% of self‐reports coincided with observable piloerection, a bias unrelated to piloerection intensity, anatomical location, heart‐rate variability, or interoceptive awareness. We also discovered a self‐report bias for the forearm, contradicting the observation that piloerection occurs with equal frequency on multiple anatomical locations. Finally, there was low correspondence between self‐reports of being “emotionally moved” and observed piloerection. These counterintuitive findings not only highlight a disconnect between an obvious physiological response and our capacity for self‐monitoring, but they underscore a fascinating divergence between human and non‐human species. Although piloerection is vital in non‐human organisms, the connection between piloerection and psychological experience in humans may be less significant than previously assumed, possibly due to its diminished evolutionary relevance

Single-cell analysis tools for drug discovery and development

The genetic, functional or compositional heterogeneity of healthy and diseased tissues presents major challenges in drug discovery and development. Such heterogeneity hinders the design of accurate disease models and can confound the interpretation of biomarker levels and of patient responses to specific therapies. The complex nature of virtually all tissues has motivated the development of tools for single-cell genomic, transcriptomic and multiplex proteomic analyses. Here, we review these tools and assess their advantages and limitations. Emerging applications of single cell analysis tools in drug discovery and development, particularly in the field of oncology, are discussed

Genetically programmed chiral organoborane synthesis

Recent advances in enzyme engineering and design have expanded nature’s catalytic repertoire to functions that are new to biology. However, only a subset of these engineered enzymes can function in living systems. Finding enzymatic pathways that form chemical bonds that are not found in biology is particularly difficult in the cellular environment, as this depends on the discovery not only of new enzyme activities, but also of reagents that are both sufficiently reactive for the desired transformation and stable in vivo. Here we report the discovery, evolution and generalization of a fully genetically encoded platform for producing chiral organoboranes in bacteria. Escherichia coli cells harbouring wild-type cytochrome c from Rhodothermus marinus8 (Rma cyt c) were found to form carbon–boron bonds in the presence of borane–Lewis base complexes, through carbene insertion into boron–hydrogen bonds. Directed evolution of Rma cyt c in the bacterial catalyst provided access to 16 novel chiral organoboranes. The catalyst is suitable for gram-scale biosynthesis, providing up to 15,300 turnovers, a turnover frequency of 6,100 h^(–1), a 99:1 enantiomeric ratio and 100% chemoselectivity. The enantiopreference of the biocatalyst could also be tuned to provide either enantiomer of the organoborane products. Evolved in the context of whole-cell catalysts, the proteins were more active in the whole-cell system than in purified forms. This study establishes a DNA-encoded and readily engineered bacterial platform for borylation; engineering can be accomplished at a pace that rivals the development of chemical synthetic methods, with the ability to achieve turnovers that are two orders of magnitude (over 400-fold) greater than those of known chiral catalysts for the same class of transformation. This tunable method for manipulating boron in cells could expand the scope of boron chemistry in living systems

Piloerection persists throughout repeated exposure to emotional stimuli

It is often suggested that piloerection, or goosebumps, is primarily triggered by emotional experience—theoretical perspectives place a heavy emphasis on experiencing novelty and surprise. However, the two studies described here challenge this perspective, demonstrating that the incidence of piloerection is not contingent upon exposure to novel stimuli and is disconnected from self-reported emotions. Study 1 (N = 80) shows that piloerection was not more likely to occur among individuals exposed to unfamiliar stimuli compared to those with prior exposure. Additionally, self-reported emotions were not correlated with observed piloerection. Study 2 (N = 27) found that piloerection persists throughout multiple exposures to identical stimuli. Importantly, the trajectories of observed piloerection and self-reported emotions diverged greatly. These findings challenge the common view that piloerection—unlike self-reported goosebumps and chills—is driven by emotional experience, suggesting that it may not be as closely connected to emotional experiences as previously theorised