ABOUT REGENERATION OF ALIEN POLYCHAETE POLYDORA WEBSTERI (ANNELIDA: SPIONIDAE)

2021 ◽  
Vol 14 (3) ◽  
pp. 24-31
Author(s):  
E. V. Lisitskaya ◽  
N. A. Boltachova
Keyword(s):  
Water Temperature ◽  
Inverse Relationship ◽  
Direct Relationship ◽  
The Body ◽  
The Black Sea ◽  
Regenerative Capacity ◽  
Body Segments ◽  
Minimum Number ◽  
Oyster Farm ◽  
Number Of Segments

New data on the regenerative capacity of the invader polychaete Polydora websteri Hartman in Loosanoff & Engle, 1943 have been obtained. The material was collected in 2019-2020 in the area of Sevastopol. Polychaetes were extracted from blisters in the valves of an exotic oyster species for the Black Sea - Crassostrea gigas (Thunberg, 1793). Molluscs were grown on an oyster farm. Polychaetes were kept in aquariums with filtered seawater at a temperature from 8.8 to 25.8 °C and a salinity of 17.5-17.8‰. Under laboratory conditions, body segments were removed from the worms and their recovery was observed. It was found that P. websteri regenerated both the anterior and posterior parts of the body. The minimum number of segments capable to simultaneously restore both anterior and posterior regions is three mid-body segments. The regeneration process in P. websteri depends significantly on the water temperature. In the range of 8.8-26 °С, a direct relationship was established between the water temperature and the number of regenerated individuals. An inverse relationship was found between the water temperature and the time spent on regenerating the lost fragments. When warming up the water, the proportion of regenerated P. websteri increased from 15 to 87%, and the duration of regeneration decreased 2.5 times.

Body size and segmentation patterns in free-living and parasitic polychaetes

2001 ◽  
Vol 79 (5) ◽  
pp. 741-745 ◽  
Author(s):  
Robert Poulin
Keyword(s):  
Life History ◽  
Body Length ◽  
Life History Traits ◽  
The Body ◽  
Free Living ◽  
Body Segments ◽  
The Family ◽  
Body Sizes ◽  
Number Of Segments ◽  
Over Time

Taxa that include both free-living and parasitic lineages present opportunities to examine if and how the life-history traits of parasitic organisms have diverged from those of their free-living relatives. In a comparative analysis the body sizes and numbers of body segments of parasitic polychaetes of the family Oenonidae were compared with those of free-living polychaetes from closely related families. There was no difference in body length between oenonids and free-living polychaetes. However, the parasitic oenonids attain, on average, a much higher number of body segments than their free-living counterparts. The number of segments per unit body length is also much higher in oenonids than in related free-living polychaetes. This suggests that new segments are produced at a higher rate or for longer periods in oenonids than in free-living polychaetes, in which the proliferation of new segments slows down over time to allow for the segments to grow in size. Given that each segment can produce gametes late in the life of the worm, the proliferation of segments in oenonids may be an adaptation to their parasitic life-style.

scholarly journals The finding of a rare in the Black Sea polychaete Ctenodrilus serratus (Schmidt, 1857) (Annelida, Cirratulidae)

2020 ◽  
Vol 5 (2) ◽  
pp. 109-111
Author(s):  
E. V. Lisitskaya ◽  
N. A. Boltachova
Keyword(s):  
Water Temperature ◽  
Black Sea ◽  
Morphological Characteristics ◽  
The Black Sea ◽  
Single Specimen ◽  
Schematic Representation ◽  
Bottom Soil ◽  
Sevastopol Bay ◽  
Oyster Farm

In July 2019, three polychaetae specimens of the genus Ctenodrilus were found in oyster cages on silted oyster shells. The cages from a mussel-and-oyster farm located at the outer roadstead of Sevastopol Bay were suspended at a depth of 6–8 m. The bottom soil under the mussel-and-oyster farm is silted sand, and the depth is of 16 m. During the sampling, water temperature was of +23 °C, and the salinity was of 17.7 ‰. Thus, according to morphological characteristics, polychaetae we found should be classified as Ctenodrilus serratus (Schmidt, 1857). Photographs of alive and fixed polychaetae, chaetae patterns, and a schematic representation of their number by segments are presented. At the beginning of the XX century, a single specimen of this species was found in the Black Sea.

scholarly journals Minimum Number of Experimental Data for the Thermal Characterization of a Hot Water Storage Tank

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4741
Author(s):  
María Gasque ◽  
Federico Ibáñez ◽  
Pablo González-Altozano
Keyword(s):  
Experimental Data ◽  
Water Temperature ◽  
Temperature Profile ◽  
Storage Tank ◽  
Water Storage ◽  
Hot Water ◽  
Experimental Temperature ◽  
Inlet Temperature ◽  
Water Storage Tank ◽  
Minimum Number

This paper demonstrates that it is possible to characterize the water temperature profile and its temporal trend in a hot water storage tank during the thermal charge process, using a minimum number of thermocouples (TC), with minor differences compared to experimental data. Four experimental tests (two types of inlet and two water flow rates) were conducted in a 950 L capacity tank. For each experimental test (with 12 TC), four models were developed using a decreasing number of TC (7, 4, 3 and 2, respectively). The results of the estimation of water temperature obtained with each of the four models were compared with those of a fifth model performed with 12 TC. All models were tested for constant inlet temperature. Very acceptable results were achieved (RMSE between 0.2065 °C and 0.8706 °C in models with 3 TC). The models were also useful to estimate the water temperature profile and the evolution of thermocline thickness even with only 3 TC (RMSE between 0.00247 °C and 0.00292 °C). A comparison with a CFD model was carried out to complete the study with very small differences between both approaches when applied to the estimation of the instantaneous temperature profile. The proposed methodology has proven to be very effective in estimating several of the temperature-based indices commonly employed to evaluate thermal stratification in water storage tanks, with only two or three experimental temperature data measurements. It can also be used as a complementary tool to other techniques such as the validation of numerical simulations or in cases where only a few experimental temperature values are available.

Annual variations in body-size spectra of planktonic ciliate communities and their relationships to environmental conditions: a case study in Jiaozhou Bay, northern China

2012 ◽  
Vol 93 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Henglong Xu ◽  
Yong Jiang ◽  
Wei Zhang ◽  
Mingzhuang Zhu ◽  
Khaled A. S. Al-Rasheid ◽  
...  
Keyword(s):  
Body Size ◽  
Water Temperature ◽  
Environmental Conditions ◽  
Jiaozhou Bay ◽  
Northern China ◽  
The Body ◽  
The Yellow Sea ◽  
Size Spectra ◽  
Annual Variations ◽  
Planktonic Ciliate

The annual variations in body-size spectra of planktonic ciliate communities and their relationships to environmental conditions were studied based on a 12-month dataset (June 2007 to May 2008) from Jiaozhou Bay on the Yellow Sea coast of northern China. Based on the dataset, the body sizes of the ciliates, expressed as equivalent spherical diameters, included five ranks: S1 (5–35 μm); S2 (35–55 μm); S3 (55–75 μm); S4 (75–100 μm); and S5 (100–350 μm). These body-size ranks showed a clear temporal succession of dominance in the order of S2 (January–April) → S1 (May–July) → S4 (August–September) → S3 (October–December). Multivariate analyses showed that the temporal variations in their body-size patterns were significantly correlated with changes in environmental conditions, especially water temperature, salinity, dissolved oxygen concentration (DO) and nutrients. In terms of abundance, rank S2 was significantly correlated with water temperature, DO and nutrients, whereas ranks S4 and S5 were correlated with the salinity and nutrients respectively (P < 0.05). These results suggest that the body-size patterns of planktonic ciliate communities showed a clear temporal pattern during an annual cycle and significantly associated with environmental conditions in marine ecosystems.

Rattlesnake strike behavior: kinematics

1998 ◽  
Vol 201 (6) ◽  
pp. 837-850 ◽  
Author(s):  
K V Kardong ◽  
V L Bels
Keyword(s):  
High Speed ◽  
Predatory Behavior ◽  
The Body ◽  
Body Postures ◽  
Body Segments ◽  
Impact Forces ◽  
Tactile Stimuli ◽  
High Speed Film ◽  
Rodent Prey ◽  
Subsequent Loss

The predatory behavior of rattlesnakes includes many distinctive preparatory phases leading to an extremely rapid strike, during which venom is injected. The rodent prey is then rapidly released, removing the snake's head from retaliation by the prey. The quick action of the venom makes possible the recovery of the dispatched prey during the ensuing poststrike period. The strike is usually completed in less than 0.5 s, placing a premium on an accurate strike that produces no significant errors in fang placement that could result in poor envenomation and subsequent loss of the prey. To clarify the basis for effective strike performance, we examined the basic kinematics of the rapid strike using high-speed film analysis. We scored numerous strike variables. Four major results were obtained. (1) Neurosensory control of the strike is based primarily upon sensory inputs via the eyes and facial pits to launch the strike, and upon tactile stimuli after contact. Correction for errors in targeting occurs not by a change in strike trajectory, but by fang repositioning after the jaws have made contact with the prey. (2) The rattlesnake strike is based upon great versatility and variation in recruitment of body segments and body postures. (3) Forces generated during acceleration of the head are transferred to posterior body sections to decelerate the head before contact with the prey, thereby reducing impact forces upon the snake's jaws. (4) Body acceleration is based on two patterns of body displacement, one in which acute sections of the body open like a gate, the other in which body segments flow around postural curves similar to movements seen during locomotion. There is one major implication of these results: recruitment of body segments, launch postures and kinematic features of the strike may be quite varied from strike to strike, but the overall predatory success of each strike by a rattlesnake is very consistent. &lt;P&gt;

Music in migrant camps as a medium creating non-narrative human relationships

2021 ◽  
Vol 12 (1) ◽  
pp. 347-360
Author(s):  
Julien Labia
Keyword(s):  
At Risk ◽  
Personal Identity ◽  
Direct Relationship ◽  
The Body ◽  
Verbal Art ◽  
Problematic Situation ◽  
Human Relationships ◽  
The Real ◽  
Musical Interactions ◽  
Expressive Activity

A migrant camp is a ‘non-place’ where personal identity is put at risk. Music is a means of personal adaptation in camps, even if it means allowing little place for the real reasons for displacement of the very people shaping these new hybridizations of music. The present power of music in such a place is to create strong relationships, ‘shortcutting’ both narration and the longer time needed in order to create relationships. The kind of personal advantage it is for someone to be a musician is a topic surprisingly forgotten, obscured by theoretical habits of seeing music essentially as an expressive activity directed to an audience, or as being a communicative activity. Music has a performative power different from language, as a non-verbal art having a strong and direct relationship to the body. Musical interactions on the field give migrants the ability to balance their problematic situation of refugees, shaping a real present.

Laonicespecies (Polychaeta, Spionidae) from the Whittard Canyon (NE Atlantic) with descriptions of two new species

2017 ◽  
Vol 97 (5) ◽  
pp. 961-973 ◽  
Author(s):  
Andrey Sikorski ◽  
Laetitia M. Gunton ◽  
Lyudmila Pavlova
Keyword(s):  
New Species ◽  
North Atlantic ◽  
Deep Water ◽  
The Body ◽  
Identification Key ◽  
The Other ◽  
Ne Atlantic ◽  
Two New Species ◽  
Generic Groups ◽  
Number Of Segments

Four species ofLaonice(Annelida: Spionidae) were collected from the lower bathyal depths (3300–3700 m) in the Whittard Canyon, NE Atlantic. Two are herewith described as new species:Laonice whittardensissp. nov. andLaonice nataesp. nov. The other two areLaonice blakeiSikorski & Jirkov, 1988 andLaonice magnacristataMaciolek, 2000.Laonice whittardensishas genital pouches appearing from chaetiger 3, prostomium free of peristomium and bidentate hooks.Laonice nataebelongs to the subgenusAppelloefianov. with prostomium distinct from the peristomium, more than two vertical rows of capillaries in several anterior chaetigers, genital pouches present on a limited number of segments or totally absent. However, the absence of pronounced anterior widening of the body together with anterior branchiae, which are remarkably (nearly twice) longer than the notopodial postchaetal lobes, the narrow lanceolate notopodial postchaetal lobes, the pronounced pointedness of all postchaetal lobes (both notopodial and neuropodial) in the anterior half of body at least, and absence of genital pouches and the size of the body all distinguishL. nataefrom other species belonging to this subgenus. An identification key to all nine known deep-water (>400 m depth)Laonicespecies in North Atlantic is given and four previously recognized sub-generic groups are formally named:Laonice, Sarsianasubgen. nov.,Appelloefiasubgen. nov.,Norgensiasubgen. nov.

scholarly journals Minimum Cell Connection in Line Segment Arrangements

2017 ◽  
Vol 27 (03) ◽  
pp. 159-176
Author(s):  
Helmut Alt ◽  
Sergio Cabello ◽  
Panos Giannopoulos ◽  
Christian Knauer
Keyword(s):  
Linear Time ◽  
Optimal Solution ◽  
Time Algorithm ◽  
Linear Time Algorithm ◽  
Constant Number ◽  
Line Segments ◽  
Straight Line ◽  
Minimum Number ◽  
Number Of Segments ◽  
Connection Problems

We study the complexity of the following cell connection problems in segment arrangements. Given a set of straight-line segments in the plane and two points [Formula: see text] and [Formula: see text] in different cells of the induced arrangement: [(i)] compute the minimum number of segments one needs to remove so that there is a path connecting [Formula: see text] to [Formula: see text] that does not intersect any of the remaining segments; [(ii)] compute the minimum number of segments one needs to remove so that the arrangement induced by the remaining segments has a single cell. We show that problems (i) and (ii) are NP-hard and discuss some special, tractable cases. Most notably, we provide a near-linear-time algorithm for a variant of problem (i) where the path connecting [Formula: see text] to [Formula: see text] must stay inside a given polygon [Formula: see text] with a constant number of holes, the segments are contained in [Formula: see text], and the endpoints of the segments are on the boundary of [Formula: see text]. The approach for this latter result uses homotopy of paths to group the segments into clusters with the property that either all segments in a cluster or none participate in an optimal solution.

Nephtyidae (Annelida: Polychaeta) from the Sea of Marmara and Black Sea, with descriptions of two new species

Zootaxa ◽  
2021 ◽  
Vol 5060 (2) ◽  
pp. 33-64
Author(s):  
SEVGI KUŞ ◽  
GÜLEY KURT ◽  
MELIH ERTAN ÇINAR
Keyword(s):  
New Species ◽  
Body Size ◽  
Black Sea ◽  
The Body ◽  
The Black Sea ◽  
Sea Of Marmara ◽  
Marine Fauna ◽  
Black Sea Coast ◽  
Two New Species ◽  
Sea Coast

The present paper deals with the diversity of nephtyid polychaetes (Nephtyidae) from the Sea of Marmara and the Black Sea. Three species belonging to two genera (Micronephthys and Nephtys) were found in the Black Sea (coast of Turkey) and six species belonging to three genera (Inermonephtys, Micronephthys and Nephtys) were found in the Sea of Marmara. The material includes two species new to science, Inermonephtys turcica n. sp. and Nephtys sinopensis n. sp., and a species record (Nephtys kersivalensis McIntosh, 1908) new to the Sea of Marmara’s marine fauna. Nephtys sinopensis n. sp. is mainly characterized by having 1–4 geniculate chaetae in the postacicular position of the parapodia; digitiform antennae, palps, and ventral cirri at chaetiger 1 with swollen tips; small and cirriform branchiae present from chaetiger 4 to the end of the body; poorly developed parapodial prechaetal lamellae in median and posterior chaetigers and long ventral cirri along the body. Inermonephtys turcica n. sp. is mainly characterized by having cushion-like palps with digitiform tips; well developed neuropodial postchaetal lamellae; barred chaetae in preacicular position of the anterior and median parapodia; and branchiae first appearing between chaetiger 3 and 13 (depending on body size).  

INVESTIGATION OF THE ISSUES OF NUTRITION OF STUDENTS USING THE DEFINITION OF PHYSICAL ACTIVITY

2021 ◽  
Author(s):  
Maria Alexandrovna Kozlova ◽  
Anna Nikolaevna Filatova
Keyword(s):  
Physical Activity ◽  
Nutritional Status ◽  
Direct Relationship ◽  
The Body ◽  
Adequate Nutrition ◽  
Daily Diet ◽  
Nutrition And Physical Activity ◽  
Definition Of ◽  
The Relationship ◽  
Practical Recommendations

The article touches upon the question of the relationship between proper nutrition and physical activity. A study of the nutritional status and lifestyle of students was carried out. The assessment was carried out according to several criteria: the daily diet and its components (this gave an idea of the substances that the body may lack), bad habits and the degree of employment in work or educational activities. The results of the study showed that there is a direct relationship between adequate nutrition and physical activity. Practical recommendations for adjusting the daily diet are given. Attention is focused on food products containing the greatest amount of vitamins and minerals, which, according to the results of the research, were not enough for students.

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