Implications of long‐distance movements of frugivorous rain forest hornbills

Long‐distance seed dispersal influences many critical ecological processes by improving chances of gene flow and maintaining genetic diversity among plant populations. Accordingly, large‐scale movements by frugivores may have important conservation implications as they provide an opportunity for long‐distance seed dispersal. We studied movement patterns, resource tracking, and potential long‐distance seed dispersal by two species of Ceratogymna hornbills, the black‐casqued hornbill C. atrata, and the white‐thighed hornbill C. cylindricus, in lowland tropical forests of Cameroon. We determined fruiting phenology of 24 tree species important in hornbill diet at monthly intervals and compared these patterns to monthly hornbill census data. After capture and radio‐tagging of 16 hornbills, we used radio telemetry by vehicle and fixed wing aircraft to determine the extent of long‐distance movements. Hornbills exhibited up to 20‐fold changes in numbers in response to fruit availability in our 25 km² study area. Also, hornbills made large‐scale movements up to 290 km, which are larger than any movement previously reported for large avian frugivores. Together, these observations provide direct evidence that hornbills are not resident and that hornbills track available fruit resources. Our results suggest that Ceratogymna hornbills embark on long‐distance movements, potentially dispersing seeds and contributing to rain forest regeneration and diversity.     

Biodiversity and the Heterogeneous Disturbance Regime on Military Training Lands

Disproportionately large numbers of threatened and endangered species and unusually high biodiversity occur on active and former military training areas. Although this may seem paradoxical given the apparently destructive nature of military training, an evaluation of the nature and extent of the disturbances is enlightening. Military training frequently produces heterogeneous landscapes. Large portions of military training areas remain virtually untouched, favoring disturbance‐averse species; other portions are heavily disturbed, favoring disturbance‐dependent species. The rich habitat mosaics include the two extremes as well as the continua of disturbance and succession between them, thus providing suitable habitat for a very large number of species with widely varying habitat requirements. To explain the phenomenon, a heterogeneous disturbance hypothesis is proposed which suggests that biodiversity is maximized where multiple kinds, frequencies, severities, periodicities, sizes, shapes, and/or durations of disturbance occur concomitantly on a landscape in a spatially and temporally distributed fashion. The enhanced biodiversity occurring on active and former military training areas illustrates the need for restoration ecologists to restore or maintain an appropriate heterogeneous disturbance regime when attempting to restore ecosystem function and biodiversity.     

Epidermal growth factor receptor internalization rate is regulated by negative charges near the SH2 binding site Tyr992.

This study examines the effects of mutations at and in the vicinity of tyrosine 992 of the epidermal growth factor receptor (EGFr) on epidermal growth factor- (EGF-) stimulated internalization of the receptor. Two regions of the EGFr adjacent to this domain have been defined previously as internalization domains. The present work shows that the mutation of negatively charged amino acid residues near Tyr992 to their uncharged analogues increases the rate of EGF receptor internalization. In addition, the conversion of Tyr992, which is an EGFr ligand-induced autophosphorylation site, to phenylalanine also increases the rate of receptor internalization. However, the mutation of Tyr992 to a glutamate residue does not alter the receptor internalization rate. In addition, the truncation of the EGFr at glutamate 996 reduces the internalization rate by half. This result confirms previous reports that residues immediately C-terminal to Glu996 are necessary to allow the normal rate of ligand-induced receptor endocytosis. The data suggest that negative charge in the vicinity of Tyr992, and potentially the phosphorylation of the EGFr at Tyr992, reduces the rate of ligand-induced receptor endocytosis. This reduction in internalization rate increases the lifetime of the activated EGFr in the plasma membrane by about 70%, thus suggesting that phosphorylation of Tyr992 acts to increase the signaling capacity of the EGF receptor even as it directly acts as an SH2 binding site.     

Mastication and enamel microstructure in <Emphasis Type="Italic">Cambaytherium</Emphasis>, a perissodactyl-like ungulate from the early Eocene of India

The dentition of Cambaytherium was investigated in terms of dental wear, tooth replacement and enamel microstructure. The postcanine tooth row shows a significant wear gradient, with flattened premolars and anterior molars at a time when the last molars are only little worn. This wear gradient, which is more intensive in Cambaytherium thewissi than in Cambaytherium gracilis, and the resulting flattened occlusal surfaces, may indicate a preference for a durophagous diet. The tooth replacement (known only in C. thewissi) shows an early eruption of the permanent premolars. They are in function before the third molars are fully erupted. During the dominant phase I of the chewing cycle the jaw movement is very steep, almost orthal, with a slight mesiolingual direction and changes into a horizontal movement during phase II. The enamel microstructure shows Hunter-Schreger-bands (HSB) in the inner zone of the enamel. In some teeth the transverse orientation of the HSB is modified into a zig-zag pattern, possibly an additional indicator of a durophagous diet.     

Outcomes of endoscopic ultrasound‐guided pancreatic FNAC diagnosis for solid and cystic lesions at Manchester Royal Infirmary based upon the Papanicolaou Society of Cytopathology pancreaticobiliary terminology classification scheme

Objective

To compare endoscopic ultrasound (EUS)‐FNAC diagnosis of pancreatic lesions with patient outcome based upon the Papanicolaou Society of Cytopathology pancreaticobiliary terminology classification scheme diagnostic categories: Panc 1 (non‐diagnostic); Panc 2 (negative for malignancy/neoplasia); Panc 3 (atypical); Panc 4B (neoplastic, benign); Panc 4O (neoplastic, other); Panc 5 (suspicious of malignancy); and Panc 6 (positive/malignant).

Methods

All EUS‐FNA pancreas specimens taken at Manchester Royal Infirmary in 2015 were prospectively classified according to the above scheme at the time of cytology reporting and data recorded prospectively. Subsequently, outcomes based on clinical follow‐up or histopathology diagnosis were compared with the cytology diagnosis.

Results

120 EUS‐FNA pancreas specimens from 111 patients were received, of which 112 (93.3%) specimens had follow‐up data. There were 79 and 41 EUS‐FNA pancreas specimens from solid and cystic lesions, respectively. Based on the cytology diagnosis the specimens were classified as Panc 1 (7.5%), Panc 2 (33.3%), Panc 3 (2.5%), Panc 4B (2.5%), Panc 4O (15.0%), Panc 5 (3.3%) and Panc 6 (35.9%). The performance indicators for diagnosis of malignancy or neoplasia with malignant potential, included sensitivity (95.4%), specificity (100%), positive predictive value (100%), negative predictive value (92.3%), false positive rate (0%) and false negative rate (4.6%).

Conclusions

The Papanicolaou Society of Cytopathology pancreaticobiliary terminology classification scheme is a logical system that can easily be introduced in a diagnostic cytopathology service. This classification scheme acts as an aid to diagnostic reporting, clear communication of significant results including risk of neoplasia/malignancy to clinicians, clinical audit and comparison of results with other centres.