Fruit volatile analysis using an electronic nose.

Numerous and diverse physiological changes occur during fruit ripening, including the development of a specific volatile blend that characterizes fruit aroma. Maturity at harvest is one of the key factors influencing the flavor quality of fruits and vegetables. The validation of robust methods that rapidly assess fruit maturity and aroma quality would allow improved management of advanced breeding programs, production practices and postharvest handling. Over the last three decades, much research has been conducted to develop so-called electronic noses, which are devices able to rapidly detect odors and flavors. Currently there are several commercially available electronic noses able to perform volatile analysis, based on different technologies. The electronic nose used in our work (zNose, EST, Newbury Park, CA, USA), consists of ultra-fast gas chromatography coupled with a surface acoustic wave sensor (UFGC-SAW). This technology has already been tested for its ability to monitor quality of various commodities, including detection of deterioration in apple; ripeness and rot evaluation in mango; aroma profiling of thymus species; C(6) volatile compounds in grape berries; characterization of vegetable oil and detection of adulterants in virgin coconut oil. This system can perform the three major steps of aroma analysis: headspace sampling, separation of volatile compounds, and detection. In about one minute, the output, a chromatogram, is produced and, after a purging cycle, the instrument is ready for further analysis. The results obtained with the zNose can be compared to those of other gas-chromatographic systems by calculation of Kovats Indices (KI). Once the instrument has been tuned with an alkane standard solution, the retention times are automatically converted into KIs. However, slight changes in temperature and flow rate are expected to occur over time, causing retention times to drift. Also, depending on the polarity of the column stationary phase, the reproducibility of KI calculations can vary by several index units. A series of programs and graphical interfaces were therefore developed to compare calculated KIs among samples in a semi-automated fashion. These programs reduce the time required for chromatogram analysis of large data sets and minimize the potential for misinterpretation of the data when chromatograms are not perfectly aligned. We present a method for rapid volatile compound analysis in fruit. Sample preparation, data acquisition and handling procedures are also discussed

Farm Income Stabilization: A Central Goal for American and European Policies

The central thesis developed in this paper is that snapshot views of the global measures of agricultural support mask what is really happening in U.S. and E.U. agricultural policies. We demonstrate that American and European farmers are effectively protected from market risk by these policies. The level of PSE is largely determined by the level of world price. Most economists do not pay much attention to the role of agricultural policies in income stability. Yet farm income stability is clearly a prime objective of government policy both in the E.U. and the U.S. and probably elsewhere. We need to turn out attention to this objective if we are to produce policy analysis relevant to real world policy decisions.agricultural policy, market risks, agricultural income, U.S., E.U., agricultural and natural resource economics, Agricultural and Food Policy,

Challenges Encountered By the Principals in Their Performance of the Various Operational Management Tasks Areas in Secondary Schools in Nairobi County, Kenya

All the heads of schools are tasked with the responsibility of promoting student academic achievement through organization and management of curriculum in schools. There are circumstances which hinder principals from fulfilling this responsibility to the letter. This implies that principals are facing challenges in their daily routine of promoting student academic performances. This study sought to find out the challenges encountered by the principals in their performance of the various operational management task areas in secondary schools in Nairobi County, Kenya. It adopted both qualitative and quantitative methods. The target population was all the principals/deputy principals, heads of departments, teachers, students’ leaders and members of the Boards of Management of all public secondary schools in Nairobi County. A sample of 30 schools and their 30 principals / deputy principals, 60 heads of departments, 120 teachers, 180 student leaders and 20 members of the Boards of Management participated in the study. Stratified random technique was used to select the schools, the teachers and the heads of departments to participate in the study. All principals/deputy principals, senior student leaders and their student leaders and heads of Board of Management of the selected schools automatically participated in the study while the other student leaders and other members of Board of Management were selected through random sampling procedure. Data was collected using questionnaires, focus group discussion and interview guide. The quantitative data collected was analysed using Statistical Package for Social Sciences (SPSS) version 22.0. The findings of the study established that the principals faced various challenges in performance of the administrative tasks. These challenges included; inadequate funds, shortage of teachers, student indiscipline, teacher indiscipline, drug abuse, teenage pregnancies, political interference, weak student leader’s bodies and poor school community relations. The study recommends that training of principals is of utmost importance so that the current and prospective principals possess the requisite certification in school management and this training of principals should also emphasize human relations skills to help them cope with students and staff personnel problems. Keywords: Principals, Performance, Challenges, Operational Managemen

The Role of Guidance and Counselling in Curbing Students’ Strikes in Secondary Schools in Nairobi County, Kenya

The youth constitute the highest number of Kenya's population and due to their enormous number the society expects them to play a vital role in its future development. However, this expectation may not be tenable due to their deviant behaviour such as marked increase in the number of secondary school unrests and strikes in the Schools. This study sought to find out the role of guidance and counselling in curbing students’ strikes in secondary schools in Nairobi County, Kenya. It adopted descriptive research design. The target population in this study consisted of all principals and deputy principals in all public secondary schools in Nairobi County. Stratified random sampling method was used in selecting the sample schools, principals and deputy principals. Data was collected using questionnaires and interview guides. The quantitative data collected was analysed using Statistical Package for Social Sciences (SPSS) version 20. The findings of the study established that guidance and counselling units in learning institutions were not effective. Most of the guidance and counselling teachers provided guidance and counselling services irregularly or at crisis times since they devoted most of their time to completing the syllabus and therefore did not have time to detect the students’ problems early enough. Unless these units were strengthened, they served little purpose in curbing student strikes. The study recommends that frequency of offering guidance and counselling services in schools should be increased and guidance and counselling departments in schools should be strengthened. The study also recommends that guidance and counselling programmes should be extended to the parents. This means that parents should be educated in order to take a more active role in the guidance and counselling of their children so that these services are provided both at home and in school. Keywords: Role, Guidance and Counselling, Student Strike

Ways Through Which Principals Acquire the Leadership Competencies Required for Effective Management of Secondary Schools in Nairobi County, Kenya

The last two decades have seen principals in Kenya come under heavy criticism over some serious cases of mismanagement that resulted in some of the worst institutional accidents, disasters/tragedies, unrests and even social and economic crimes that Kenya has witnessed. This study sought to find out ways that principals acquire the leadership competencies required for effective management of secondary schools in Nairobi County. It adopted both qualitative and quantitative methods. The target population was all the principals/deputy principals, heads of departments, teachers, students’ leaders and members of the Boards of Management of all public secondary schools in Nairobi County. A sample of 30 schools and their 30 principals/deputy principals, 60 heads of departments, 120 teachers, 180 student leaders and 20 members of the Boards of Management participated in the study. Stratified random technique was used to select the schools, the teachers and the heads of departments to participate in the study. All principals/deputy principals, senior student leaders and their student leaders and heads of Board of Management of the selected schools automatically participated in the study while the other student leaders and other members of Board of Management were selected through random sampling procedure. Data was collected using questionnaires, focus group discussion and interview guide. The quantitative data collected was analysed using Statistical Package for Social Sciences (SPSS) version 11.5. The findings of the study established that , leadership competencies were acquired through pre-service, in-service and on-the-job training.  In pre-service training, the principals who had a bachelor’s degree had been exposed to a one unit course in education administration in the universities. The unit was also offered as an area of specialization at masters level in public and private universities for those principals who had masters degrees. Keywords: Principals, Leadership, Competencies, Effective Managemen

Suicide -- Causation, Indicators and Interventions

Excerpt from the full-text article: In this paper an attempt is made to determine what factors propel given individuals toward self destruction. Durkheim\u27s typology of suicides is utilized and an analysis of the social and psychological components of each type undertaken. The social structure is viewed from the vantage point of how it influences and is internalized by members of society. The psychological aspects are handled by looking into what intrapsychic and external forces shape the individual\u27s personality and behavior in such a way that he seeks his own death. In some instances it is hard to draw a sharp line of demarcation between the social and psychologtcal; as many factors are psychosocial. Psychoanalytic psychtatry postulates that the fundamental patterns of behavior are set in tnfancy and early childhood and are not seriously altered later. Neurosis can not be cured by social analysis; this is the task of psychotherapy. Each indtvtdual has a certain level of suicide potenttal that is established during his early life by his family and immediateenvironment through such behavior as rejection or over acceptance; frustration or total gratification of wishes. If the child is not gradually prepared for responsible adulthood, his suicide potential is apt to be htgh. Conversely, if his rearing readies him for work and other activities which will net him socially valued rewards, his suicide potential will be low. Even though an act of suicide may appear to be precipitated by a specific cause, one stimulus alone is not sufficient to produce self murder. The underlying pattern of behavior must be already leading in that direction