Bulb Size Research Articles

TEST RESULTS FOR CLONES OF GARLIC

A large number of forms and varieties of garlic created in the selection process allowed this culture to spread almost all over the world: in temperate regions, in subtropics and even in tropical regions. Currently, the world's acreage of garlic is 1.438 million hectares, the average yield is 16.9 tons per hectare, the gross yield is 24.255 million tons. The largest producers of garlic are China, India, South Korea and Egypt. The highest yield was recorded in Uzbekistan, Egypt, China, Tadjikistan. In Uzbekistan, it is grown everywhere, mainly on household plots and small areas in farms. In the republic, varieties of garlic are South-violet (1972) and May VIR (1978). Since 2004, the Surkhandarya Scientific Experimental Station of the VegetableMelon Crops and Potato Research Institute has been conducting selection work to create new varieties of garlic. As a result of the research, the Chidamli variety was introduced and, since 2016, introduced into the State Register. All zoned varieties belong to the group of autumn-sprouting varieties. In 2011- 2015, about 100 promising clones of garlic were evaluated in the south of Uzbekistan. The effectiveness of selection for the size of bulbs and teeth is revealed. Clones with a mass of bulbs and teeth are isolated. Clones with a bulb weight of more than 80 g and a tooth mass of more than 6 g are distinguished. They are a valuable source for the creation of high-yielding varieties of garlic in Uzbekistan.

Genetic Deletion of Soluble Epoxide Hydroxylase Causes Anxiety-Like Behaviors in Mice.

Soluble epoxide hydrolase (sEH), an enzyme with COOH-terminal hydrolase and NH2-terminal lipid phosphatase activities, is expressed in regions of the brain such as the cortex, white matter, hippocampus, substantia nigra, and striatum. sEH is involved in the regulation of cerebrovascular and neuronal function upon pathological insults. However, the physiological significance of sEH and its underlying mechanism in modulating brain function are not fully understood. In this study, we investigated the role of sEH in anxiety and potential underlying mechanisms in mice. Western blot for protein phosphorylation and expression was performed. Immunohistochemical analyses and Nissl and Golgi staining were performed for histological examination. Mouse behaviors were evaluated by open field activity, elevated plus maze, classical fear conditioning, social preference test, and Morris water maze. Our results demonstrated that the expression of sEH was upregulated during postnatal development in wild-type (WT) mice. Genetic deletion of sEH (sEH-/-) in mice resulted in anxiety-like behavior and disrupted social preference. Increased olfactory bulb (OB) size and altered integrity of neurites were observed in sEH-/- mice. In addition, ablation of sEH in mice decreased protein expression of tyrosine hydroxylase and reduced dopamine production in the brain. Moreover, the level of phosphorylated calmodulin kinase II (CaMKII) and glycogen synthase kinase 3 α/β (GSK3α/β) was higher in sEH-/- mice than in WT mice. Collectively, these findings suggest that sEH is a key player in neurite outgrowth of neurons, OB development in the brain, and the development of anxiety-like behavior, by regulating the CaMKII-GSK3α/β signaling pathway.

Development of seed propagated shallot (Allium cepa L var. aggregatum) varieties in Ethiopia

Abstract Shallot is one of the major vegetable crops used for seasoning local cuisines in Ethiopia. It is propagated vegetatively using bulbs as planting material. However, the use of bulbs as planting material is not advisable, because bulbs are expensive, bulky to transport, transmit diseases from one generation to the next, and have short shelf life. As a result, production of shallot decreased considerably in favor of the seed propagated onions. To reverse the trend, a study was undertaken to develop shallot varieties that can be propagated through seed. In the first phase of the development, sixty nine shallot accessions, that could bolt and produce seeds, were identified. Three accessions (DZSHT-91-2B, DZSHT-193-1A and DZSHT-157-1B), which had desirable bulb characteristics were developed through recurrent positive selection from 2008 to 2014. Then the three varieties were compared with an onion variety Bombay Red, a vegetatively propagated shallot variety Minjar and an introduced seed propagated shallot variety Vethalan. The trials were lied out in Randomized Complete Block Design with three replications at three different agro-ecological locations. The results of the study showed that the three varieties, in addition to mitigating the aforementioned problems, had 44–86% higher bulb yield and higher proportion of big and medium size bulbs as compared to shallot variety Minjar. The yield and total soluble solids (TSS) of the varieties were comparable with Bombay Red and Vethalan varieties. The three selected seed producing cultivars also produced seed yield of 6.0–10.4 g per plant. Therefore, the varieties will benefit shallot bulb and seed producers, transporters and traders.

Spermathecae morphology of some Tephritinae (Diptera: Tephritidae) species: A scanning electron microscope study

Spermathecal structure of five species [ Campiglossa producta (Loew, 1844) , Campiglossa tessellata (Loew, 1844) , Euaresta bullans (Wiedemann, 1830) , Tephritis formosa (Loew, 1844) , Tephritis nigricauda (Loew, 1856)] from subfamily Tephritinae were examined using light and scanning electron microscopy. The specimens were collected between 1999 and 2013 from various provinces of Turkey. Spermathecae were coated in gold/palladium with a Emitech SC 7620 Sputter Coater and examined with a Jeol 6390 LV scanning electron microscope (SEM) operated at 10 kV. Spermathecal structures were characterized as spermathecal bulb, pumping region and spermathecal channel. Descriptions of the spermathecal structures, size of spermathecal bulb, aspect ratio of spermathecal bulb and SEM micrographs of spermathecae are presented for each species.

Factors Affecting Planting Depth and Standing of Rice Seedling in Parachute Rice Transplanting

Parachute rice transplanting is a simple and practical rice transplanting method. It can be done manually or mechanically, with various possible designs of machines or tools. This research aimed at quantitatively formulating related factors to the planting depth and standing of rice seedling. Parachute seedlings of rice were grown at several sizes of parachute soil bulb sizes. The trays were specially designed with a 3D printer having bulb sizes 7, 8, 9, 10 mm in square sides and 15 mm depth. At seedling ages of 8-12 days after sowing the seedling bulbs were drops into puddled soil. Soil hardness was set at 3 levels of hardness, measured in hardness index using golf ball test. Angle of dropping was set at 3 levels: 0°, 30°and 45° from the vertical axis. The height of droppings was set at 100 cm, 75 cm, and 50 cm. The relationship between bulb size, height of dropping, soil hardness, dropping angle and planting depth was formulated with ANN. Most of input variables did not significantly affect the planting depth, except that hard soil significantly differs from mild soil and soft soil. The dropping also resulted in various positions of the planted seedlings: vertical standing, sloped, and falling. However, at any position of the planted seedlings, the seedlings would recover themselves into normally vertical position. With this result, the design of planting machinery, as well as the manual planting operation, can be made easier.

Dynamic changes in ejaculatory bulb size during Drosophila melanogaster aging and mating

The ejaculatory bulb of Drosophila melanogaster males produces proteins and pheromones that play important roles in reproduction. This tissue is also the final mixing site for the ejaculate before transfer to the female. The ejaculatory bulb’s dynamics remain largely unstudied. By microscopy of the ejaculatory bulb in maturing adult males, we observed that the ejaculatory bulb expands in size as males age. Moreover, we document that when males mate, their ejaculatory bulb expands further as ejaculate transfer begins, and then contracts halfway through the course of mating as ejaculate transfer finishes. Although there is some male-to-male variation in the timing of these changes, ultimately the tissue changes in a predictable pattern that gives insight into the active mating process in Drosophila.

Analysis on the Consumption of Farmers about Lily Bulb

Lily, which is the one of three major cut flowers in Korea, is very important agricultural product but lily industry is recently sinking. One of main problems causing the weak competitiveness of lily industry is high cost of lily bulb which is usually imported. Most lily bulbs consumed in Korea are imported from Netherlands. Thus, Korean government keeps trying to increase the market share of Korean lily bulb but it is not easy. The purpose of this paper is to analyse the lily bulb consumption in Korea and to suggest the strategies to promote the Korean lily bulb consumption. The results of study in this paper present a few findings useful as follows: First, as a conjoint analysis result, it arranged in order of reusing (37.2%, high, normal, low), size of bulb (30.9%, large, medium, small), bulb quality (16.7%, tissue culture, scale propagation), and production area (15.1%, domestic ․imported). Second, it is important to increase the reliability of Korean lily bulb and to promote the Korean lily bulb farmer, in order to improve the supply environment for Korean lily bulb. Third, the larger Lily market for the larger lily bulb market is necessary. Especially, strategies to expand the market size of cut flower and non-flower should be developed.

Biomass and Accumulation of Potassium, Calcium, and Magnesium in Gladiolus as Affected by Heat Units and Corm Size

ABSTRACTIn México, gladiolus is an important crop cultivated in the central part of the country. In ornamental geophytes, the size of bulbs is a critical factor, impacting plant growth and quality. The objective of the present study was to model the accumulation of potassium (K), calcium (Ca) and Magnesium (Mg) in gladiolus plants as affected by corm size (3.5, 3.0 and 2.5 cm). Regardless of corm size, total dry mass of plants accumulated in three different stages. The initial stage occurred during the corm sprouting phase and continued through the vegetative phase, ending either shortly before (plants from 3.5 cm corms), at (plants from 3.0 cm corms) or shortly after (plants from 2.5 cm corms) the heading phase. The second stage, on which the plants exhibited a rapid dry mass accumulation, occurred shortly before or shortly after the heading phase, finishing with the elongation of the flowering stem. The third stage showed the highest dry mass accumulation rate, coinciding with the elongation of the flowering stem and ending at the blooming of the spike. To complete all the phenological phases, gladiolus required 1818 heat units regardless of corm size. Not considering the nutrients provided by the corm, gladiolus required a total of 6.33, 5.59 and 5.01 mmol plant−1 of K, 2.22, 1.69 and 1.38 mmol plant−1 of Ca and 2.49, 2.00 and 1.68 mmol plant−1 of Mg when grown from 3.5, 3.0, and 2.5 cm corms. At the beginning of the vegetative phase, plants tended to increase Ca content at the expense of K, whereas the proportion of Mg remained unaffected, however, between the vegetative and heading phases, the proportion of Ca declined while that of K and Mg increased. At the end of the study, the proportion of K was much higher than that of Ca and Mg, whereas the proportion of Ca and Mg was similar.

Digital cranial endocast of Riograndia guaibensis (Late Triassic, Brazil) sheds light on the evolution of the brain in non-mammalian cynodonts

A digital cranial endocast of the specimen UFRGS-PV-596-T of Riograndia guaibensis was obtained from μCT scan images. This is a small cynodont, closely related to mammaliaforms, from the Late Triassic of Brazil. Riograndia has large olfactory bulb casts and the cerebral hemispheres region is relatively wider than in other non-mammaliaform cynodonts. Impressions of vessels were observed and a conspicuous mark on the dorsal surface was interpreted as the transverse sinus. The calculated encephalization quotient is greater than the range seen in most other non-mammaliaform cynodonts. The ratios between linear and area measurements of the dorsal surface suggest four evolutionary changes from a basal eucynodont morphology to mammaliaforms, involving an evolutionary increase of the relative size of the olfactory bulbs and the width of the cerebral hemispheres and cerebellum. The data supports the hypothesis of the neurological evolution of the mammalian lineage starting with a trend for an increase of the olfactory bulbs, which is associated with adaptations in the nasal cavity. This trend is suggested to be linked to the selective pressures for small-sized faunivorous, and probably nocturnal, animals, and represents an initial improvement of the sensory receptor system, subsequently leading to further development of the ‘superior’ structures for sensorial processing and integration.

Performance Evaluation of Onion (Allium Cepa L.) Varieties at Benatsemay Woreda of South Omo Zone, Ethiopia

Onion varieties were evaluated for adaptability to the climatic conditions in Benatsemay woreda. Three varieties of onion were planted under a complete randomized block design experiment with three replications at farmer’s field at Benatsemay woreda. Yield and yield component data like; plant height, number of leaves, bulb size and bulb yield of each varieties were collected. Bulb of all onion varieties were harvested at their maturity stage (90% tops down) and then weighted. SAS were used for data analysis. The result indicated that, the three varieties namely; Adama red, Nasick red and local contribute similarly to total yield, plant height, number of leaves and bulb size. The variety local was the best variety as it produced the highest bulb yield of 7.0033kg/plot numerically. Based on the result, we advise farmers to use local variety followed by Nasick red and Adama red therefore, government should promote these onion varieties for cultivation in Benatsemay woreda especially for Beneta kebele and its vicinity. Concerning body has to work together to ensure the availability of the seed of Local and Nasick red varieties. So that, onion producer can be interested for accepting these varieties for large scale production. The effects of different agricultural practices on yield of onion have to be considered for future investigation.

Field Assessment of Onion Genotypes for Resistance against Purple Blotch Complex (Alternaria porri And Stemphylium vesicarium) under Artificial Epiphytotic Conditions in Indian Punjab

A total of forty one genotypes of onion were evaluated for their relative response to purple blotch complex caused by Alternaria porri and Stemphylium vesicarium under artificial epiphytotic condition in field during Rabi 2014-2015 and 2015-2016. Significant variation in disease severity among the onion genotypes was found over two years but the pooled analysis revealed that most of the variations were due to genotype x year interaction. None of the genotypes exhibited resistance to the disease complex. Of the test genotypes, eighteen were found moderately susceptible while twenty one were found susceptible to the disease complex. Two genotypes viz., Punjab Naroya and OSR-1364 exhibited highly susceptible reaction. However, six genotypes viz., P-96, P-30, P-121, OSR-1359, P-98 and OSR-1370 showed superior yield performance. Purple blotch complex exhibited highly significant negative correlation of 0.71 and 0.67 with fresh bulb yield and bulb size, respectively. Cluster analysis of onion genotypes was performed based on disease and yield variables and the genotypes were furthered grouped into five clusters based on average values of disease and yield variables.Int. J. Appl. Sci. Biotechnol. Vol 5(4): 498-504

Kif1bp loss in mice leads to defects in the peripheral and central nervous system and perinatal death

Goldberg-Shprintzen syndrome is a poorly understood condition characterized by learning difficulties, facial dysmorphism, microcephaly, and Hirschsprung disease. GOSHS is due to recessive mutations in KIAA1279, which encodes kinesin family member 1 binding protein (KIF1BP, also known as KBP). We examined the effects of inactivation of Kif1bp in mice. Mice lacking Kif1bp died shortly after birth, and exhibited smaller brains, olfactory bulbs and anterior commissures, and defects in the vagal and sympathetic innervation of the gut. Kif1bp was found to interact with Ret to regulate the development of the vagal innervation of the stomach. Although newborn Kif1bp−/− mice had neurons along the entire bowel, the colonization of the gut by neural crest-derived cells was delayed. The data show an essential in vivo role for KIF1BP in axon extension from some neurons, and the reduced size of the olfactory bulb also suggests additional roles for KIF1BP. Our mouse model provides a valuable resource to understand GOSHS.

Experimental and Numerical Studies of the Excess Pore Pressure Field Surrounding an Advancing Spudcan Footing

The rapid jack-in process of spudcan footing tends to generate substantial build-up of excess pore pressure below the spudcan underside. An intimate knowledge of the excess pore pressure concentration is thus of significance for understanding both the short-term and long-term mechanical behavior of spudcan. As yet there is a dearth of information in this area. This paper presents a comprehensive research to explore the pattern and magnitude of the excess pore pressure field surrounding an advancing spudcan. Both centrifuge experiments and effective-stress large deformation finite element analyses (LDFEAs) were involved, while the former served mainly to benchmark the latter and the latter provided a complete information database of the excess pore pressure. The bulb-shaped excess pore pressure concentration zone was identified below the spudcan underside. Sizes of pressure bulbs as well as the magnitudes of excess pore pressures inside them bore close relationship to the penetration depths and soil's properties. The results of parametric study led to the development of a simple yet useful approach to estimate the spudcan-penetration-induced excess pore pressure in soil without carrying out the complicated computation. Necessary charts and tables were provided to facilitate its usage. It is expected that the development of such an approach can aid the practicing engineer to obtain a quick and rough estimate of excess pore pressure generated in the midst of the jack-up spudcan penetration and prepare for its short-term and long-term implications.

Incremento del tamaño y peso del bulbo de cebolla (Allium cepa L.) por translocación de nutrientes

La cebolla (Allium cepa L.) es la segunda hortaliza alimenticia más importante a nivel mundial después del tomate y genera numerosos empleos. Asimismo, el rendimiento promedio en Sinaloa es bajo con relación a otras partes de México y del Mundo. En esta investigación se buscó conocer el incremento del tamaño y peso del bulbo de cebolla blanca, desde el momento de doblado de la hoja hasta su cosecha. Se utilizó la variedad “Carta Blanca” (Nunhems) que es de días cortos. Se realizó un muestreo aleatorio simple en una superficie de tres hectáreas. Se realizaron tres mediciones, con un intervalo de una semana entre ellas. Las mediciones iniciaron cuando se dobló la hoja. Para realizar el análisis estadístico, se verificó la normalidad de los datos y se realizó la prueba de homogeneidad. Los datos se sometieron a análisis de varianza y comparación media de Tukey (p< 0.05) con el paquete estadístico SAS. También se realizó un análisis de sensibilidad para estimar la viabilidad económica. Los resultados muestran que al inicio del doblado de la hoja, el diámetro medio del bulbo ecuatorial fue de 7.48 cm, después de una semana los bulbos fueron de 8.02 cm (diferencia de 0.53 cm). En la segunda semana la diferencia con respecto al inicio de la hoja plegada fue de 0.78 cm. Además, durante la tercera semana los bulbos de cebolla han parado el crecer, al mismo tiempo que las hojas pierden el color verde. Esto demuestra que la translocación continúa incluso después de haber alcanzado la madurez fisiológica de la planta que se manifiesta plegando la hoja. El análisis de sensibilidad indica que si las cebollas se vendieran a 4 pesos y cosecharan una semana después del doblado de la hoja, el beneficio extra sería de $ 17 903.78 con una cantidad de 100 mil plantas por hectárea y hasta $ 71 615.13 con 400 mil plantas. Además, dos semanas después del doblado, las ganancias serían de $ 26 363.18 y $ 105 452.70 respectivamente.

Optimisation of grease application to railway tracks

Trackside lubricators are designed to deliver grease to passing wheel flanges to reduce wheel and rail wear on curves. Ensuring that they are set up to deliver sufficient grease for the range of vehicles passing a site can be a challenge. For example, vehicle dynamics modelling and site investigations have shown that the wheels of passenger vehicles do not run as close to the rail face as those of freight vehicles, meaning that they are less likely to contact the grease and lubricate subsequent curves. To investigate the effects of different trackside devices, and the influence of parameters governing grease pickup, including lateral wheel displacement and pump durations, a bespoke test rig was built at the University of Sheffield. The rig used a scaled wheel, a short section of rail and a modern trackside lubricator set-up. Experiments involving different lateral wheel displacements and pumping durations were carried out, in addition to the visualisation of the size of the grease bulb. This showed how a grease bulb grows. It also indicated that a worn profile is likely to require greater wheel displacement to make contact with grease bulbs when compared to a new wheel profile. The experimental results showed that increasing pickup of grease can be expected when an additional component called a GreaseGuide™ was fitted to a regular grease delivery unit (GDU) on the rail. The efficiency of grease pickup was investigated, and test results exploring increasing pump durations have indicated a relationship between pickup and bulb size. To validate the use of the scaled rig, similar tests were carried out using a full-scale test rig. The full-scale results were compared to the experimental results of the scaled wheel rig. This showed that whilst there were differences between the two test rigs in absolute values and anomalous results, overall trends were the same on both test scales. The effect of temperature on bulb size and pumpability of grease was also investigated. This work can be extended further by using the same method to investigate other parameters that affect the lubrication of curves. This can lead to optimised lubricator set-up to ensure that the track is fully lubricated all the time.

Studies of life history of Gagea graeca (Liliaceae) based on morphological and molecular methods

BackgroundWe studied the life history of Gagea graeca (L.) A. Terracc. (sect. Anthericoides) by field surveys on the Greek island of Crete, including quantitative analyses of 405 individuals, estimation of resource allocation by measuring the nitrogen content of different plant organs, assessing seed set and recording genetic diversity via amplified fragment length polymorphism (AFLP) analyses. In contrast to most species of the genus G. graeca seems to be a short-lived perennial, developing several characters that are rather typical for annual plants.ResultsAlthough seed set varies largely, flowering plants produce many (68 ± 79) small, flattened seeds (mean weight 73 ± 22 µg) in comparison to a single bulbil. If measured as nitrogen content of the respective plant parts, investment in seeds (25%) is much higher than that in bulbils (4%). In addition, the threshold for flower formation (expressed as bulb size where 50% of the plants form the respective structure) is with 2.17 ± 0.05 mm lower than that for bulbils with 2.80 ± 0.16 mm. This is in accordance with AFLP analyses revealing predominantly sexual reproduction (only 9.1% of 110 investigated plants belonged to clones).ConclusionIn the genus Gagea early, predominantly sexual reproduction seems to be characteristic for species from arid habitats, coupled with a low proportion of clonal plants.

Alterations in yield, physicochemical components and mineral composition of onion following organic manure and inorganic nitrogen application

ABSTRACTOnion is the one of the most important vegetable crops grown extensively throughout the world; hence, understanding the response of the crop to the form and amount of N provided is of immense importance. In a field experiment, poultry and cattle manure (at 10 t/ha) were compared with four inorganic nitrogen (N) application levels (0, 60, 90 and 120 kg N/ha), and six combinations of manure and N applications were investigated. Plant growth and total yield (kg/ha) significantly increased, when N application increased from 0 to 120 kg/ha, with or without added poultry manure. Plant height, leaf number and neck thickness were significantly reduced at 0 kg/ha N plus cattle manure. The bulb ascorbic acid concentration significantly increased with the use of poultry manure (15.94 mg/100 g) and cattle manure (15.94 mg/100 g), compared with 120 kg/ha inorganic N (11.42 mg/100 g). No significant effects were observed on total phenolics and total soluble solids of onion bulbs following the different fertiliser treatments. Cattle manure increased P and K concentrations, whilst poultry manure significantly increased Zn and Fe concentrations in onion bulbs. Onion bulb Ca and Mg concentrations were lower when cattle manure (0.19% and 0.12%) was used than when other organic or inorganic fertilisers were used. Therefore, organic manure increases the concentrations of certain minerals in onions, compared with inorganic N application, without negatively affecting bulb size.

Effect of planting methods and irrigation levels on water productivity of onion (Allium cepa L.)

To investigate the effect of planting methods and irrigation levels on irrigation water productivity and onion (Allium cepa L.) yield, a field experiment was conducted on sandy loam soil at the Research Farm of Department of Soil Science, Punjab Agricultural University, Ludhiana during rabi 2011-12. Three planting methods tested include drip irrigated beds, furrow irrigated beds and flat flood irrigation. In drip irrigated beds and furrow irrigated beds three onion rows were planted on 55 cm wide beds at a spacing of 15 cm from row to row. Three levels of irrigation water were tested i.e. IW/PAN-E ratio of 0.3, 0.4 and 0.5 in drip irrigated onions and 1.2, 1.6 and 2.0 in both bed furrow and flat flood methods of irrigation. The results of the experiment indicated that in drip irrigated beds by applying same quantity and 50 per cent of water as of flat flood irrigation, the yield was increased by 43 and 25 per cent, respectively. Irrespective of irrigation levels, highest onion yield (32.5 t ha-1) was recorded under drip irrigated beds followed by furrow irrigated beds (28.5 t ha-1) and least under flat flood irrigation method (25.0 t ha-1). The onion yield increases with the increase in irrigation level in all the planting methods. The highest irrigation water productivity was observed under drip irrigated beds (1.26 t ha-1 cm) followed by furrow irrigated beds (0.84 t ha-1 cm) and least under flat flood irrigation (0.48 t ha-1 cm) with equivalent IW/PAN-E ratios. Bigger size onions (40 mm and 50 mm) were observed under drip irrigated beds followed by furrow irrigated beds and smallest size bulbs under flat flood method of irrigation. The results revealed that drip irrigation could successfully be used for onion production with significant water saving and higher production.

Quantitative analysis of effects of hemodynamic stress on temporal variations of cardiac phases in models of human carotid bulbs.

In this study, we evaluated the hemodynamics of carotid artery models with carotid bulbs of various sizes using computational fluid dynamics (CFD) and the Fluent CFD software. The oscillatory shear index (OSI) and flow velocity distribution were evaluated in carotid models without a carotid bulb and with carotid bulbs of known geometry (major axis of 10, 11, 12, 13, and 14mm; carotid bifurcation angle of 50°). Furthermore, the diameters of the common carotid artery, the external carotid artery, and the internal carotid artery were defined as 7.2, 4.0, and 4.5mm, respectively. The accuracy of the CFD analysis in this study was verified using a flow phantom and measuring velocities with phase-contrast cine magnetic resonance imaging. The CFD parameters were defined as follows: rigid and no-slip walls, pulsatile flow, and 0Pa of peripheral pressure. The OSI in the carotid bulb tended to show a high value during the expansion of the carotid bulb (maximum and minimum OSI: 0.11±0.08 at d bulb: 14mm; 0.0013±0.0011 at no bulb), and the region of high OSI expanded with the expansion of the carotid bulb. The flow separated near the carotid bulb, and the flow deceleration expanded downstream as the size of the bulb increased. These findings suggest that the size of the carotid bulbs contributed to the OSI because the larger bulbs exhibited higher OSI values. The relation between the OSI and the carotid bulb size could serve as a risk indicator for atherosclerosis.

The Evolution of Olfactory Capabilities in Wild Birds: A Comparative Study

Modern birds possess an olfactory apparatus similar to that of other vertebrates, yet the major evolutionary forces that drove the evolution of diversity in olfactory capabilities in birds remain elusive. Several non-mutually exclusive evolutionary scenarios for the evolution of olfactory capability in birds have been proposed. Olfactory capability may have evolved due to its role in recognition in social contexts. In addition, olfactory capability may have evolved because it provides a selective advantage in foraging or navigation. Finally, olfactory capability could be favored whenever the ecological conditions of species hindered the use of other senses and/or favored olfaction. Here we evaluate predictions from these hypotheses in a comparative study using a species-level phylogeny of 142 bird species and considering the indirect effects of some predictors on others. We find an interactive effect of aquatic dependence and diet on the size of the olfactory bulb: vegetarian and omnivore birds living in aquatic environments have larger olfactory bulbs than terrestrial birds, whereas species with an animal diet, aquatic and terrestrial species have similar-sized olfactory bulbs. In addition, the size of the olfactory bulb was weakly related with social complexity, with colonial species having relatively larger olfactory bulb than solitary breeders or those forming small aggregations. Our results suggest that the role of foraging in driving enhancements in the avian olfactory apparatus is contingent on ecological conditions that may affect the transmission of odor-based signals. This provides evidence for the largely neglected possibility that the evolution of the olfactory apparatus of birds has been driven by the interaction between ecological and behavioral traits, rather than being solely due to main effects of these traits.