A case of elongated styloid process in a modern-age skull from Puerto Cabello, Venezuela

Background: The styloid process (SP) arises from cartilage of the second branchial arch and tends to calcify during later life. If the length of the SP is more than 30 mm, it can be considered abnormally elongated. Clinical symptoms associated with elongation of this type are defined as Eagle’s syndrome. The paper presents a case of an elongated SP in a modern skull from Puerto Cabello, Venezuela, obtained from a series of skulls of African slaves kept at the Department of Anthropology, Polish Academy of Sciences in Wroclaw. Materials and methods: The skull belonged to a male individual, aged ca. 55 years at death (maturus). In terms of basic anthropometric features it had slightly greater facial width parameters in comparison to the cerebral part, and a shorter length of neurocranium when compared to average values of morphological features in African skulls from Uganda. Results: Further macroscopic analysis revealed the presence of an elongated SP (ca. 70.1 mm) with secondary lesions remaining after a healed fracture. Imaging of the bone structure of the elongated SP was carried out using a computed to­mography scan, with multilevel image analysis without contrast. The elongation and calcification of the left ligament in anterior orientation could have caused irritation to the structure of cranial nerves, running within the parapharyngeal space, and to sympathetic fibres running in the wall of cervical arteries. Conclusions: Analyses of craniological materials recovered during excavations or as part of old osteological collections are rare due to the fragility of this bone structure, and for that reason they may be a valuable source of information on the health status of historic human populations

Matrix stiffness modulates the activity of MMP-9 and TIMP-1 in hepatic stellate cells to perpetuate fibrosis

Liver fibrosis is characterised by a dense and highly cross-linked extracellular matrix (ECM) which promotes progression of diseases such as hepatocellular carcinoma. The fibrotic microenvironment is characterised by an increased stiffness, with rigidity associated with disease progression. External stiffness is known to promote hepatic stellate cell (HSC) activation through mechanotransduction, leading to increased secretion of ECM components. HSCs are key effector cells which maintain the composition of the ECM in health and disease, not only by regulating secretion of ECM proteins such as collagen, but also ECM-degrading enzymes called matrix metalloproteinases (MMPs) and their inhibitors (TIMPs). Uninhibited MMPs degrade ECM proteins to reduce external rigidity. Using fibronectin-coated polyacrylamide gels to alter substrate rigidity without altering ligand density, we show that fibrotic rigidities downregulate MMP-9 expression and secretion, and also upregulate secretion of TIMP-1, though not its expression. Using tissue immunofluorescence studies, we also report that the expression of MMP-9 is significantly decreased in activated HSCs in fibrotic tissues associated with hepatocellular carcinoma. This suggests the presence of a mechanical network that allows HSCs to maintain a fibrotic ECM, with external rigidity providing feedback which affects MMP-9 and TIMP-1 secretion, which may become dysregulated in fibrosis

Matrix stiffness modulates the activity of MMP-9 and TIMP-1 in hepatic stellate cells to perpetuate fibrosis

Liver fibrosis is characterised by a dense and highly cross-linked extracellular matrix (ECM) which promotes progression of diseases such as hepatocellular carcinoma. The fibrotic microenvironment is characterised by an increased stiffness, with rigidity associated with disease progression. External stiffness is known to promote hepatic stellate cell (HSC) activation through mechanotransduction, leading to increased secretion of ECM components. HSCs are key effector cells which maintain the composition of the ECM in health and disease, not only by regulating secretion of ECM proteins such as collagen, but also ECM-degrading enzymes called matrix metalloproteinases (MMPs) and their inhibitors (TIMPs). Uninhibited MMPs degrade ECM proteins to reduce external rigidity. Using fibronectin-coated polyacrylamide gels to alter substrate rigidity without altering ligand density, we show that fibrotic rigidities downregulate MMP-9 expression and secretion, and also upregulate secretion of TIMP-1, though not its expression. Using tissue immunofluorescence studies, we also report that the expression of MMP-9 is significantly decreased in activated HSCs in fibrotic tissues associated with hepatocellular carcinoma. This suggests the presence of a mechanical network that allows HSCs to maintain a fibrotic ECM, with external rigidity providing feedback which affects MMP-9 and TIMP-1 secretion, which may become dysregulated in fibrosis

Highly specific and non-invasive imaging of Piezo1-dependent activity across scales using GenEPi

Mechanosensing is a ubiquitous process to translate external mechanical stimuli into biological responses. Piezo1 ion channels are directly gated by mechanical forces and play an essential role in cellular mechanotransduction. However, readouts of Piezo1 activity are mainly examined by invasive or indirect techniques, such as electrophysiological analyses and cytosolic calcium imaging. Here, we introduce GenEPi, a genetically-encoded fluorescent reporter for non-invasive optical monitoring of Piezo1-dependent activity. We demonstrate that GenEPi has high spatiotemporal resolution for Piezo1-dependent stimuli from the single-cell level to that of the entire organism. GenEPi reveals transient, local mechanical stimuli in the plasma membrane of single cells, resolves repetitive contraction-triggered stimulation of beating cardiomyocytes within microtissues, and allows for robust and reliable monitoring of Piezo1-dependent activity in vivo. GenEPi will enable non-invasive optical monitoring of Piezo1 activity in mechanochemical feedback loops during development, homeostatic regulation, and disease

Anchors aweigh: the sources, variety, and challenges of mission drift

The growing number of studies which reference the concept of mission drift imply that such drift is an undesirable strategic outcome related to inconsistent organizational action, yet beyond such references little is known about how mission drift occurs, how it impacts organizations, and how organizations should respond. Existing management theory more broadly offers initial albeit equivocal insight for understanding mission drift. On the one hand, prior studies have argued that inconsistent or divergent action can lead to weakened stakeholder commitment and reputational damage. On the other hand, scholars have suggested that because environments are complex and dynamic, such action is necessary for ensuring organizational adaptation and thus survival. In this study, we offer a theory of mission drift that unpacks its origin, clarifies its variety, and specifies how organizations might respond to external perceptions of mission drift. The resulting conceptual model addresses the aforementioned theoretical tension and offers novel insight into the relationship between organizational actions and identity

Ocena i porównanie wskaźników produkcyjnych w stadzie zachowawczym i podstawowym merynosa polskiego w starym typie

The aim of this study was to determine basic production indices in the conservation flock of old-type Polish Merino Sheep and to compare them with the production results of the whole sheep flock of this breed kept on the Boguszyn farm belonging to the Lubiana Pedigree Breeding Establishment. Reproduction performance of dams as well as growth and rearing of their offspring in the period 2007–2009 were evaluated. Single born (birth type) dams predominated (56.8–62.9%) in both flocks. The percentage of twin births was approx. 38% for the ewes in the foundation flock and over 44% for those in the conservation flock. In the age structure of sheep from both flocks in the years 2007–2009, young sheep at the age of 2 to 5 years predominated, which could have affected the reproduction results of the dams. The mean body weight of all the evaluated lambs at 2 days of age was 4.14 kg. The lambs born in 2009 were the lightest. Their body weights were 3.55 kg and 3.69 kg in the foundation and conservation flocks, respectively. Statistically significantly heavier (P≤0.01) lambs were born in the conservation flock.Also, lambs from this flock gained significantly higher body weight (21.89–22.33 kg) at 56 days of age in the years 2008–2009, compared with the range of 17.85–21.84 kg for the lambs from the foundation flock in the period 2007–2009. The daily body weight gains in both flocks ranged from 240 g to 333 g and were statistically significantly better (P≤0.01) in the conservation flock. In both flocks, the significant effect of birth type and sex of lambs on their body weight and daily body weight gains was shown.Celem pracy było określenie podstawowych wskaźników produkcyjnych w stadzie zachowawczym merynosa polskiego w starym typie i ich porównanie z wynikami produkcyjnymi całego stada owiec tej rasy w gospodarstwie Boguszyn należącym do Ośrodka Hodowli Zarodowej Lubiana. Ocenie poddano użytkowość reprodukcyjną matek oraz wzrost i odchów ich potomstwa za lata 2007–2009. W obu stadach przeważał pojedynczy typ urodzenia matek (56,8–62,9%). Odsetek bliźniaczego typu urodzenia maciorek kształtował się w stadzie podstawowym na poziomie ok. 38%, zaś w stadzie zachowawczym wynosił ponad 44%. W strukturze wiekowej owiec obu stad w okresie 2007–2009 przeważały owce młode w wieku od 2. do 5. lat, co mogło mieć wpływ na wyniki rozrodu matek. Średnia masa ciała wszystkich ocenianych jagniąt mierzona w 2. dniu po urodzeniu wynosiła 4,14 kg. Najlżejsze były jagnięta rocznika 2009. Ich masa ciała w stadzie podstawowym wynosiła 3,55 kg, a w stadzie zachowawczym – 3,69 kg. Statystycznie istotnie cięższe (P≤0,01) jagnięta rodziły się w stadzie zachowawczym. Również istotnie większą masę ciała w wieku 56. dni osiągnęły w latach 2008–2009 jagnięta ze stada zachowawczego (21,89–22,33 kg) przy rozstępie 17,85–21,84 kg u jagniąt stada podstawowego w okresie 2007–2009. Dobowe przyrosty masy ciała w obu stadach wahały się w granicach od 240 g do 333 g i były statystycznie istotnie lepsze (P≤0,01) w stadzie zachowawczym. W obu stadach wykazano istotny wpływ typu urodzenia i płci jagniąt na ich masę ciała i przyrosty dobowe