The embryogenesis of the larval head of Simulium venustum Say (Diptera: Nematocera)

1969 ◽  
Vol 47 (4) ◽  
pp. 495-503 ◽  
Author(s):  
D. A. Craig

The embryogenesis of the larval head of Simulium venustum Say is reexamined, as the known accounts of simuliid embryology do not describe the origin of the cephalic fans. It is shown that the cephalic fans are derived from the premandibular appendages, that the cephalic apotome is composed of both labral and protocephalic elements, that the egg burster marks the posterior limit of the embryonic labrum, and that the ventral median portion of the larval head capsule is submental in origin. The single prothoracic proleg arises as a single structure late in development.The embryogenesis of the simuliid cephalic fans is compared with that of similar structures in other nematocerous larvae. It is concluded that the cephalic fans of simuliid and the mouth brushes of Aedes larvae are not homologous.It is proposed that the cephalic fans be renamed premandibular fans, that the postgenal cleft be renamed the submental cleft, and that the hypostomial teeth be renamed the mental teeth.

The main provisions of the concept of technology of diamond cutting and drilling of building structures are considered. The innovativeness of the technology, its main possibilities and advantages are presented. Carrying out works with the help of this technology in underwater conditions expands its use when constructing and reconstructing hydraulic structure. The use of diamond drilling equipment with motors equipped with an internal combustion engine is considered. Drilling holes with a variable diameter during the reconstruction of the runways of airfields makes it possible to combine the landing mats into a single structure. The ability to cut inside the concrete mass, parallel to the front surface, has no analogues among the methods of concrete treatment. The use of this technology for producing blind openings in the body of concrete without weakening the structure is also unique. Work with precision quality in cutting and diamond drilling of concrete and reinforced concrete was noted by architects and began to be implemented in the manufacture of inter-room and inter-floor openings. Non-destructive approach to the fragmentation of building structures allows them to be reused. The technology of diamond cutting and drilling is located at the junction of new construction, repair, reconstruction of buildings and structures, and dismantling of structures. Attention is paid to the complexity and combinatorial application of diamond technology. Economic efficiency and ecological safety of diamond technology are presented. The main directions of further research for the development of technology are indicated.


2005 ◽  
Vol 40 (4) ◽  
pp. 418-430 ◽  
Author(s):  
Markus L. Heinrichs ◽  
Brian F. Cumming ◽  
Kathleen R. Laird ◽  
J. Sanford Hart

Abstract Diatom and chironomid analysis of sediments encompassing the past 400 years from Bouchie Lake, British Columbia, suggests two distinct periods of limnological conditions. Prior to 1950 AD, Fragilaria construens and F. pinnata are the most common diatom species, and Chironomus, Procladius and Tanytarsini dominate the chironomid record. Moderately low nutrient concentrations consistent with oligo-mesotrophic lakes are inferred. From 1950, the diatom assemblage is dominated by Stephanodiscus parvus, a eutrophic indicator, whereas the chironomid communities show a relative increase in littoral taxa coincident with lower head capsule abundance. Higher nutrient levels, specifically total phosphorus, which increased from 8 µg L-1 prior to 1950 to 20 µg L-1 currently, are coincident with midge communities indicative of lower oxygen concentrations. Observed biotic changes and nutrient levels inferred from the sediment core correspond to historical land-use changes.


Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 360
Author(s):  
Pieterjan Debie ◽  
Noemi B. Declerck ◽  
Danny van Willigen ◽  
Celine M. Huygen ◽  
Bieke De Sloovere ◽  
...  

Intraoperative guidance using targeted fluorescent tracers can potentially provide surgeons with real-time feedback on the presence of tumor tissue in resection margins. To overcome the limited depth penetration of fluorescent light, combining fluorescence with SPECT/CT imaging and/or gamma-ray tracing has been proposed. Here, we describe the design and preclinical validation of a novel bimodal nanobody-tracer, labeled using a “multifunctional single attachment point” (MSAP) label, integrating a Cy5 fluorophore and a diethylenetriaminepentaacetic acid (DTPA) chelator into a single structure. After conjugation of the bimodal MSAP to primary amines of the anti-HER2 nanobody 2Rs15d and 111In-labeling of DTPA, the tracer’s characteristics were evaluated in vitro. Subsequently, its biodistribution and tumor targeting were assessed by SPECT/CT and fluorescence imaging over 24 h. Finally, the tracer’s ability to identify small, disseminated tumor lesions was investigated in mice bearing HER2-overexpressing SKOV3.IP1 peritoneal lesions. [111In]In-MSAP.2Rs15d retained its affinity following conjugation and remained stable for 24 h. In vivo SPECT/CT and fluorescence images showed specific uptake in HER2-overexpressing tumors with low background. High tumor-to-muscle ratios were obtained at 1h p.i. and remained 19-fold on SPECT/CT and 3-fold on fluorescence images over 24 h. In the intraperitoneally disseminated model, the tracer allowed detection of larger lesions via nuclear imaging, while fluorescence enabled accurate removal of submillimeter lesions. Bimodal nuclear/fluorescent nanobody-tracers can thus be conveniently designed by conjugation of a single-molecule MSAP-reagent carrying a fluorophore and chelator for radioactive labeling. Such tracers hold promise for clinical applications.


Author(s):  
Soumya K Manna ◽  
Venketesh N Dubey

Intensive and adaptive rehabilitation therapy is beneficial for post-stroke recovery. Three modes of rehabilitation are generally performed at different stages after stroke: external force-based control in the acute stage, assistive force-based rehabilitation in the midway of recovery and resistive force-based rehabilitation in the last stage. To achieve the above requirements, an innovative elbow exoskeleton has been developed to incorporate the three modes of rehabilitation in a single structure. The structure of the exoskeleton has been designed in such a way that the whole working region is divided into three where each region can provide a different mode of rehabilitation. Recovery rate can be varied for individuals since it depends on various parameters. To evaluate the rate of recovery, three joint parameters have been identified: range of angular movement, angular velocity and joint torque. These parameters are incorporated into the framework of planning a novel rehabilitation strategy, which is discussed in this article along with the structural description of the designed exoskeleton.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
James Adebayo Ojo ◽  
Adebayo Amos Omoloye

The tamarind weevil, Sitophilus linearis Herbst (Coleoptera: Curculionidae), is an important pest of tamarind and other Caesalpinioideae. Investigating its life history is important in the implementation of management strategy. Its life history was monitored daily to understand its developmental biology on tamarind seed following standard procedures under laboratory conditions of 24–30°C temperature, 60–70% relative humidity, and 12L : 12D photoperiod. The egg incubation period lasted 3.17 ± 0.07 days. A mated female of S. linearis laid an average of 165 ± 5.78 eggs during an oviposition period of 86.8 ± 2.47 days. There were four larval instars, with a total larval developmental period of 16 days. The pupal period lasted 8 days, and adult lived 108.5 ± 3.61 days. The overall growth ratio for the four instars was 1.33. There was a regular relationship and significant correlation (r=0.94) between the stages of larval development and head capsule width.


Author(s):  
R. Viswanath ◽  
H.S. Bhojya Naik ◽  
G.S. Yashavanth Kumar ◽  
P.N. Prashanth Kumar ◽  
K.N. Harish ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document