Characteristic Sizes of Life in the Oceans, from Bacteria to Whales.

The size of an individual organism is a key trait to characterize its physiology and feeding ecology. Size-based scaling laws may have a limited size range of validity or undergo a transition from one scaling exponent to another at some characteristic size. We collate and review data on size-based scaling laws for resource acquisition, mobility, sensory range, and progeny size for all pelagic marine life, from bacteria to whales. Further, we review and develop simple theoretical arguments for observed scaling laws and the characteristic sizes of a change or breakdown of power laws. We divide life in the ocean into seven major realms based on trophic strategy, physiology, and life history strategy. Such a categorization represents a move away from a taxonomically oriented description toward a trait-based description of life in the oceans. Finally, we discuss life forms that transgress the simple size-based rules and identify unanswered questions.

Kit ligand promotes the transition from primordial to primary follicles after in vitro culture of ovine ovarian tissue.

This study evaluated the effects of kit ligand (KL) on the morphology and development of ovine preantral follicles (fresh control) and after 7 days of in vitro culture in α-Minimal Essential Medium (α-MEM; control medium) or the presence of KL (1, 10, 50, 100 or 200 ng/ml). There was an increase in the percentage of primary follicles at the concentration of 100 ng/ml KL, compared with the fresh control, control medium (α-MEM) and the other KL concentrations. Follicle diameter was significantly higher than the control medium only at concentrations of 50 and 100 ng/ml KL. In conclusion, 100 ng/ml KL promoted the transition from primordial to primary follicles (follicular activation) after in vitro culture of ovine ovarian tissue.

Lower apoptosis rate in ovine preantral follicles from ovaries stored in supplemented preservation media.

The aim of this study was to investigate the effect of ovarian tissue transportation conditions (medium and period of time) on the morphology, apoptosis and development of ovine preantral follicles cultured in vitro. Each ovarian pair was cut into nine slices, with one fragment being fixed immediately (fresh control). The remaining fragments were placed individually in cryotubes containing conservation medium (minimal essential medium (MEM) without supplementation or MEM+ - with supplementation) and stored at 35ºC for 6 or 12 h without (non-cultured) or with subsequent culture for 5 days. Then, the fragments were processed for histological and terminal deoxynucleotidyl transferase (TdT) mediated dUTP nick-end labelling (TUNEL) examination. Preservation of ovarian slices in MEM or MEM+ (non-cultured) resulted in similar percentages of normal follicles when compared with the fresh control. Nevertheless, compared with the fresh control, a decrease in the percentage of normal follicles was observed in tissues cultured for 5 days. Only for tissues preserved in supplemented medium (MEM+) for 6 h, the percentage of TUNEL positive cells was similar between non-cultured tissues and tissues cultured for 5 days. Follicular activation and growth (follicular and oocyte diameter) were higher in cultured tissues than in fresh control or non-cultured tissues, except those from fragments preserved for 6 h in MEM and then cultured for 5 days in which no growth was observed. In conclusion, ovine ovarian tissue was successfully preserved in supplemented medium (MEM+) at a temperature close to physiological values (35°C) for up to 6 h without affecting apoptosis in the ovarian follicles and their ability to develop in vitro.

Photochemical responses of three marine phytoplankton species exposed to ultraviolet radiation and increased temperature: role of photoprotective mechanisms.

We carried out experiments using long-term (5-7 days) exposure of marine phytoplankton species to solar radiation, in order to assess the joint effects of ultraviolet radiation (UVR) and temperature on the photochemical responses and photoprotective mechanisms. In the experiments, carried out at Atlantic coast of Patagonia (43°18.7'S; 65°2.5'W) in spring-summer 2011, we used three species as model organisms: the dinoflagellate Prorocentrum micans, the chlorophyte Dunaliella salina and the haptophyte Isochrysis galbana. They were exposed under: (1) two radiation quality treatments (by using different filters): P (PAR, >400 nm) and PAB (PAR+UV-A+UV-B, >280 nm); (2) two radiation intensities (100% and 50%) and (3) two experimental temperatures: 18 °C and 23 °C during summer and 15 °C and 20 °C in spring experiments, simulating a 5 °C increase under a scenario of climate change. In addition, short-term (4h) artificial radiation exposure experiments were implemented to study vertical migration of cells pre- and non-acclimated to solar radiation. We observed species-specific responses: P. micans displayed a better photochemical performance and a lower inhibition induced by UVR than D. salina and I. galbana. In accordance, P. micans was the only species that showed a synthesis of UV-absorbing compounds (UVACs) during the experiment. On the other hand, non-photochemical quenching (NPQ) was activated in D. salina at noon throughout the exposure, while I. galbana did not show a regular NPQ pattern. This mechanism was almost absent in P. micans. Regarding vertical migration, I. galbana showed the most pronounced displacement to deepest layers since the first two hours of exposure in pre- and non-acclimated cells, while only non-acclimated D. salina cells moved to depth at the end of the experiment. Finally, temperature partially counteracted solar radiation inhibition in D. salina and I. galbana, whereas no effect was observed upon P. micans. In particular, significant UVR and temperature interactive effects were found in I. galbana, the most UVR sensitive species. The joint effects on UVR and temperature, and the species-specific photoprotective responses will affect the trophodynamics and production of aquatic ecosystems in a way that is difficult to predict; however the specificity of the responses suggests that not all phytoplankton would be equally benefited by temperature increases therefore affecting the balance and interaction among species in the water column.

Immunohistochemical localization of fibroblast growth factor-2 in the sheep ovary and its effects on pre-antral follicle apoptosis and development in vitro.

Studies with sheep are important to improve our knowledge about the factors that control folliculogenesis in mammals and to explore possible physiological differences among species. The aims of this study were to characterize FGF-2 protein expression in ovine ovaries and to verify the effect of FGF-2 on the morphology, apoptosis and growth of ovine pre-antral follicles cultured in vitro. After collection, one fragment of ovarian tissue was fixed for histological analysis and TUNEL analysis (fresh control). The remaining fragments were cultured for 7 days in control medium (α-MEM(+) ) alone or supplemented with FGF-2 at different concentrations (1, 10, 50, 100 or 200 ng/ml). After culturing, ovarian tissue was destined to histology and TUNEL analysis, and oocyte and follicle diameters were measured. The immunostaining for FGF-2 was observed in oocytes from primordial, primary and secondary follicles, as well as in granulosa cells of secondary and antral follicles. The percentage of normal follicles was similar among control medium, 1 and 10 ng/ml FGF-2, and significantly higher than those observed in 50, 100 or 200 ng/ml FGF-2. A significant increase in follicle diameter was observed when tissues were cultured in 10, 50, 100 or 200 ng/ml FGF-2 compared with the fresh control and the other treatments. Similar results were observed for oocyte diameter in tissues cultured with 50, 100 or 200 ng/ml FGF-2 (p < 0.05). However, the percentage of apoptotic cells only decreased (p < 0.05) in ovarian tissues cultured in 1 or 10 ng/ml FGF-2 compared with the control medium and other FGF-2 treatments. In conclusion, this study demonstrated the presence of FGF-2 in ovine ovaries. Furthermore, 10 ng/ml FGF-2 inhibits apoptosis and promotes ovine follicle growth. As the sheep ovary is more similar to that of humans, the culture system demonstrated in this work seems to be an appropriate tool for studies towards human folliculogenesis.

Identificação humana pelos eventos odontológicos e alterações dentárias de um método computadorizado / Identification dental human being for events odontologicos and alterations through a computerized method

Os dentes são os elementos sinaléticos mais resistentes de todos os tecidos do corpo, estes são importantes na identificação devido ao fato de não existirem a mesma característica dentária em dois indivíduos, sendo esta individualidade das particularidades dentárias de um ser humano um dos fatores que mais evidencia com clareza a importância deste processo na identificação. No presente trabalho, propusemos um método padronizado e computadorizado para identificação humana pelos dentes, para tanto foram utilizados dezenove cadáveres, sendo seis exumados, cinco carbonizados, três em avançado estado de putrefação e cinco em fase de esqueletizaçào. Verificamos e concluimos que a notação digital das características odontológicas pelo método adotado, nos permitiu simplificar o sistema de identificação humana pela análise dos dentes com segurança absoluta de pessoas que perderam a vida em condições trágicas quando os métodos tradicionais de identificação não puderam ser aplicados

Avaliação cronológica da cicatrização alveolar através de radiografias em humanos voltado para o interesse pericial / Avaliable chronological of the alveolar healization across of radiographic in human returned for the interest of the skill

A cicatrização dos alvéolos dentários, resultantes de exodontias, realizam-se numa seqüência cronológica que nos permite estimar o tempo decorrido entre a data da extração e a face de cicatrização alveolar, em pessoas vivas ou em cadáveres, que apresentam ausência de elementos dentários. No presente trabalho, utilizamos uma amostra de 20 pacientes, de ambos os sexos, na faixa etária de 19 a 50 anos, que se submeteram a intervenções exodônticas com controle radiográfico de 8 dias, até a cicatrização total. Concluímos que há uma seqüência cronológica da cicatrização alveolar, demonstrando que os alveolos do arco dentário superior possuem um período de cicatrização mais acelerado que os inferiores. Verificamos, também, que não houve diferenças significantes na cicatrização alveolar entre os sexos. Foram, ainda, determinadas, estatisticamente, duas funções matemáticas para os arcos dentários superior e inferior, a fim de se calcular o tempo decorrido entre a extração do dente e o nível de cicatrização alveolar

Imaging transforms for visualizing surfaces and volumes.

Three-dimensional (3D) visualization in biomedical and other imaging areas is a rapidly emerging discipline. The major developments in this field are described in a unified and concise way. To this end, we introduce an operator notation to describe the basic imaging transforms commonly used in 3D visualization and to identify a comprehensive set of basic transforms. We also introduce several new basic transforms for filtering and interpolating scenes and structures and for rendering surfaces and volumes. We demonstrate not only how the existing visualization methodologies can be described concisely, but we also show how a great variety of new methodologies can be generated using both the existing imaging transforms and the new transforms introduced in this paper. A comprehensive evaluation method to compare objectively rendering methods used in visualization based on task-specific mathematical phantoms is described. We examine in detail separate transform sequences that are best suited for rendering robust and frail structures (ie, structures with well- and poorly defined boundaries).

Medical image rendering.

Three-dimensional (3-D) visualization has recently become an established discipline in medicine. Although numerous visualization methods are currently available, a unified framework to describe and study them has been lacking. Often, the functionally independent operations in a method are integrated among themselves or with the method itself for computational efficiency. The two main aims of this article are (1) to review the methods in a unified way in a general setting so that it becomes possible to appreciate the interrelationship and interdependence of methods, and (2) to show how a variety of new methods emerge with potentially improved renditions in this unified treatment. To this end, we introduce an operator notation to describe concisely the basic 3-D imaging transforms commonly used in visualization and identify a comprehensive set of basic transforms. We describe several new basic transforms for filtering and interpolating structures and scenes, and for rendering surfaces and volumes. We show the power of the principle of treating 3-D imaging methodologies as comprising an appropriate combination of the basic operators. We show how such a treatment leads to a great variety of new rendering methods and how many such methods can lead to improved portrayal. We develop separate transform sequences to optimally render robust and frail structures (ie, structures represented in scenes with well-defined and ill-defined boundaries, respectively).

New technique for quantitation of pituitary adenoma size: use in evaluating treatment of gonadotroph adenomas with a gonadotropin-releasing hormone antagonist.

Because administration for 1 week of the GnRH antagonist Nal-Glu GnRH had been shown to decrease FSH secretion from supranormal to normal in men with gonadotroph adenomas, we investigated the effect of prolonged administration of Nal-Glu on the size of gonadotroph adenomas. To quantitate the effect of Nal-Glu GnRH on gonadotroph adenoma size, we first developed a technique for calculating adenoma volume. The technique involved collecting magnetic resonance (MR) imaging data from each adenoma at 1-mm slice intervals in the coronal, axial, and sagittal views and using the Softvu computer program to calculate adenoma volume from the MR data. The precision of this technique, as judged by the coefficients of variation of the calculations of the same view of the same study three times, was 1.7%, 1.0%, and 1.0% for each of three studies. When Nal-Glu GnRH (5 mg, sc, every 12 h) was self-administered for 3-12 months to five men with gonadotroph adenomas and supra-normal serum FSH concentrations, the serum FSH concentrations decreased to normal or below normal for the entire treatment period. Adenoma size, however, did not change during treatment in any of the five men. We conclude that calculating pituitary adenoma volume from MR data using the Softvu computer program is a highly reproducible technique, but that Nal-Glu GnRH is not an effective treatment for reducing gonadotroph adenoma size. The failure of Nal-Glu to reduce adenoma size despite its success in reducing FSH secretion suggests that FSH secretion from gonadotroph adenomas is dependent on endogenous GnRH, but growth of gonadotroph adenomas is not.

Repair of postextraction sockets: influence of homogeneous bone implants preserved by formaldehyde. An experimental study in dogs.

Small bone sticks from a dog, fixed in formaldehyde from 1 to 4 weeks, were used as homoimplants in the left postextraction sockets of dogs, and the right sockets were allowed to heal as ungrafted controls. The animals were killed 5, 11, 22, and 60 days after implantation. No obvious differences were discovered, either clinically or radiographically, between the repair of the control sockets and that of the experimental sockets. However, appreciable histologic differences could be noted. The presence of the implant disturbed and retarded both the organization of the granulation tissue and the process of intra-alveolar ossification. The attempt to use homogeneous bone implants that had been preserved in formaldehyde in order to stimulate osteogenesis in the host produced unsatisfactory results, since it retarded the process of postextraction alveolar repair.