Determination of median lethal concentration lead (II) nitrate and behavioral responses of hermit crab, Diogenes avarus

The LC50-96h test paradigm is used to measure the susceptibility and survival potential of organisms exposed to particular toxic substances, such as heavy metals. In this study, the statically acute toxicity of Pb on hermit crab D. avarus was determined according to standard methods O.E.C.D in 96h. 84 individual hermit crab with 0.19±.0.01 g weight average were used in five different treatments (75, 100, 150, 175, 200 microgram per liter of lead) with three replicates and a control treatment (15 hermit crab per in each treatment). The effective physical and chemical parameters of water including pH, total hardness, dissolved oxygen and temperature were controlled throughout the experiment. Finelly, the rate of the acute toxicity (LC50 96h) was determined to be 184.045 µg/l by using the statistic method Probity analysis. Furthermore, the rates of LC10, LC50, LC90 (24, 48, 72 and 96h) were calculated. Results indicate that when the experiment time is extended, lower concentration of Pb is leading to mortality in hermit crab D. avarus. The percentage of mortality increased with increasing duration of exposure of crab to different amounts of lead concentration. The behavioral changes observed in hermit crabs D. avarus in the experiment period included an imbalance in walking, reduced activity and movement, slow motion, no irritability and also color change of the abdomen

A morphometric study of sea urchin Echinometra mathaei (de Blainville, 1825) on beaches of Lengeh Port, Persian Gulf

Some of valuable species of Persian Gulf, such as sea urchins, are accounted less scientific studies due to the lack of any position in the local food baskets. Therefore, this survey is investigated the biometrical parameters of sea urchin Echinometra mathaei for a period of seven months (March– September, 2014) in the intertidal zone of Lengeh Port (26˚32ʹ28̋ N, 54˚52ʹ29̋ E). Random samples were collected monthly during spring tides and transferred alive to the laboratory and then the dissection and the separation of different parts of the body were started. Each part of the body length and weight was measured. By a mathematical method the volume of samples was calculated as an elliptical object. This study illustrated the largest and smallest sample were 0.07 and 103.77 grams, respectively. Results showed that the relationships between Total wet weight and Test Diameter (Total Wet Weight = 0.0053 Test Diameter2.3933), Total Wet Weight and Height (Total Wet Weight = 0.0122 Height2.5872) and Total Wet Weight and Volume (Total Wet Weight= 0.0071 Volume0.8706). The correlation coefficient between volume and total wet weight of samples was r=0.94 which shows the accuracy of Disk method. On the other hand, the HDR index was more in compared with the HWR index and it illustrates larger values of Test Diameter in compare with Height. Statical analyses prove that higher values of DWR in compared with HWR are reasonable and accurate in both sexes

Connecting Critical Hermeneutics with the Management and Organizational Studies: An Analysis of the Philosophy and Methods of its Implementation in Organizations

Critical hermeneutics is rooted in philosophy of knowledge, in general, and in the methodology of human sciences, in particular. This approach is methodologically considered as a qualitative study with the aim of achieving internal understanding in various fields such as linguistic, longitudinal and experimental sciences. Jürgen Habermas, one of the precursors of Frankfurt School, is the pioneer of this method. In 1981, he published one of his best works entitled “Communicative Interaction Theory”, and added the symbolic aspects of social interaction to Frankfurt critical theory. Thus, critical hermeneutics does not pursue a “unifying answer”; rather it seeks to portray the social phenomena that are derived through discourse. Discourse, as a means of obtaining data, is used in critical hermeneutics and as Habermas posited, the essential prerequisite for discourse is to provide space devoid of any trace of power. In this qualitative study, the researchers conducted in-depth interviews with individuals, and by transcribing the interviews, converted the phenomenon into text. These texts constitute the research data of the study. Then, the researchers interpreted the textual form of the phenomena and represented the obtained results in several limited themes, each of which is further split into certain limited categories. Since the main advantage of critical hermeneutics is developing and reorienting the existing interpretative approaches to the study of management, this paper attempts to examine this approach as a qualitative research method in organization and management studies, and represent its process and key features