The sources of knowledge of two medieval Jewish commentators in nature issues: The case of gathering the musk (Song of Songs 5:1)

Musk, which is produced from the glands of several species of deer, was a well-known perfume throughout the Mediterranean Basin in the Middle Ages. The current article examines the meaning of the gathering operation of myrrh mentioned in Song of Songs 5:1, according to R. Joseph Ibn Aknin and Naḥmanides. The two commentators argue that the phrase ariiti mori can be interpreted as the unique manner of gathering the perfume of the musk deer in its lands of origin in the Far East. They contend that harvesting the perfume refers to gathering the perfume that the deer spreads on the rocks naturally, which is a higher quality product. The two medieval rabbis were exposed to contemporary scholars or oral traditions on the way of gathering the musk. Ibn Aknin took the information from Arabic writings, such as of al-Sirāfī and al-Masʿūdī and Ibn JulJuly With regard to Naḥmanides, his source of information on gathering musk is not clear. Contribution: This article contributes to the understanding of the issue of the sources of knowledge of scholars in medieval times and how the achieved information influenced their commentaries on the Biblical Text. The current study expounds the commentators’ interpretations from a multidisplinary perspective, such as the medieval zoology and perfume industry

‘Ostrich is a Fowl for any Matter’: The ostrich as a ‘strange’ fowl in Jewish literature

The size, strange body shape and behaviour of the ostrich aroused the imagination of the ancients, Jews and non-Jews, and therefore beginning from the classical era until recent generations, various legends and beliefs were attached to it. The ancients deliberated whether the ostrich is a bird or it is a cross between a bird and a four-legged creature. In this case, Jewish writings reflected an advanced and sometimes independent conception that the ostrich is a bird. A belief that is indeed partially based on reality has to do with the food of the ostrich. In ancient sources, the ostrich is described as eating glass or metal, and according to some testimonies, this is a major component of its food. Medieval literature includes another common belief that the ostrich is gifted with miraculous powers of sight and it can use these powers to hatch the eggs by staring at them. The general impression formed from the study is that the Jews were aware of legends that existed among the nations, and even used them in their study halls for halakhic discussions and to enrich their spiritual world

‘Ostrich is a Fowl for any Matter’: The ostrich as a ‘strange’ fowl in Jewish literature

The size, strange body shape and behaviour of the ostrich aroused the imagination of the ancients, Jews and non-Jews, and therefore beginning from the classical era until recent generations, various legends and beliefs were attached to it. The ancients deliberated whether the ostrich is a bird or it is a cross between a bird and a four-legged creature. In this case, Jewish writings reflected an advanced and sometimes independent conception that the ostrich is a bird. A belief that is indeed partially based on reality has to do with the food of the ostrich. In ancient sources, the ostrich is described as eating glass or metal, and according to some testimonies, this is a major component of its food. Medieval literature includes another common belief that the ostrich is gifted with miraculous powers of sight and it can use these powers to hatch the eggs by staring at them. The general impression formed from the study is that the Jews were aware of legends that existed among the nations, and even used them in their study halls for halakhic discussions and to enrich their spiritual world

The landscape of molecular chaperones across human tissues reveals a layered architecture of core and variable chaperones

The sensitivity of the protein-folding environment to chaperone disruption can be highly tissue-specific. Yet, the organization of the chaperone system across physiological human tissues has received little attention. Through computational analyses of large-scale tissue transcriptomes, we unveil that the chaperone system is composed of core elements that are uniformly expressed across tissues, and variable elements that are differentially expressed to fit with tissue-specific requirements. We demonstrate via a proteomic analysis that the muscle-specific signature is functional and conserved. Core chaperones are significantly more abundant across tissues and more important for cell survival than variable chaperones. Together with variable chaperones, they form tissue-specific functional networks. Analysis of human organ development and aging brain transcriptomes reveals that these functional networks are established in development and decline with age. In this work, we expand the known functional organization of de novo versus stress-inducible eukaryotic chaperones into a layered core-variable architecture in multi-cellular organisms

A unique coral biomineralization pattern has resisted 40 million years of major ocean chemistry change

Today coral reefs are threatened by changes to seawater conditions associated with rapid anthropogenic global climate change. Yet, since the Cenozoic, these organisms have experienced major fluctuations in atmospheric CO2 levels (from greenhouse conditions of high pCO2 in the Eocene to low pCO2 ice-house conditions in the Oligocene-Miocene) and a dramatically changing ocean Mg/Ca ratio. Here we show that the most diverse, widespread, and abundant reef-building coral genus Acropora (20 morphological groups and 150 living species) has not only survived these environmental changes, but has maintained its distinct skeletal biomineralization pattern for at least 40 My: Well-preserved fossil Acropora skeletons from the Eocene, Oligocene, and Miocene show ultra-structures indistinguishable from those of extant representatives of the genus and their aragonitic skeleton Mg/Ca ratios trace the inferred ocean Mg/Ca ratio precisely since the Eocene. Therefore, among marine biogenic carbonate fossils, well-preserved acroporid skeletons represent material with very high potential for reconstruction of ancient ocean chemistry

Photoreactivation is the main repair pathway for UV-induced DNA damage in coral planulae

The larvae of most coral species spend some time in the plankton, floating just below the surface and hence exposed to high levels of ultraviolet radiation (UVR). The high levels of UVR are potentially stressful and damaging to DNA and other cellular components, such as proteins, reducing survivorship. Consequently, mechanisms to either shade (prevent) or repair damage potentially play an important role. In this study, the role of photoreactivation in the survival of coral planulae was examined. Photoreactivation is a light-stimulated response to UV-damaged DNA in which photolyase proteins repair damaged DNA. Photoreactivation rates, as well as the localization of photolyase, were explored in planulae under conditions where photoreactivation was or was not inhibited. The results indicate that photoreactivation is the main DNA repair pathway in coral planulae, repairing UV-induced DNA damage swiftly (K=1.75 h–1 and a half-life of repair of 23 min), with no evidence of any light-independent DNA repair mechanisms, such as nucleotide excision repair (NER), at work. Photolyase mRNA was localized to both the ectoderm and endoderm of the larvae. The amount of cell death in the coral planulae increased significantly when photoreactivation was inhibited, by blocking photoreactivating light. We found that photoreactivation, along with additional UV shielding in the form of five mycosporine-like amino acids, are sufficient for survival in surface tropical waters and that planulae do not accumulate DNA damage despite being exposed to high UVR

Mineral maturity and crystallinity index are distinct characteristics of bone mineral

The purpose of this study was to test the hypothesis that mineral maturity and crystallinity index are two different characteristics of bone mineral. To this end, Fourier transform infrared microspectroscopy (FTIRM) was used. To test our hypothesis, synthetic apatites and human bone samples were used for the validation of the two parameters using FTIRM. Iliac crest samples from seven human controls and two with skeletal fluorosis were analyzed at the bone structural unit (BSU) level by FTIRM on sections 2–4 lm thick. Mineral maturity and crystallinity index were highly correlated in synthetic apatites but poorly correlated in normal human bone. In skeletal fluorosis, crystallinity index was increased and maturity decreased, supporting the fact of separate measurement of these two parameters. Moreover, results obtained in fluorosis suggested that mineral characteristics can be modified independently of bone remodeling. In conclusion, mineral maturity and crystallinity index are two different parameters measured separately by FTIRM and offering new perspectives to assess bone mineral traits in osteoporosis