Male tilapia production techniques: A mini-review

Tilapia culture has been growing over the past decades as an excellent source of high-quality protein. Some of the Tilapia´s advantages are the ability to breed and produce new generations rapidly, tolerate shallow and turbid waters, resist a high level of disease and be flexible for culture under many different farming systems. These characteristics are the main reasons for its commercial success. However, one of them contributes to the major drawback of pond culture: the high level of uncontrolled reproduction that may occur in grow-out ponds. Uncontrolled reproduction yields to stunted growth and unmar-ketable fish due to offspring competing with the initial stock for food, besides other problems like less dissolved oxygen, greater release of ammonia and feces, heterogeneous sizes and overpopulation stress. Monosex production has been preferred in order to deal with these issues. Males are preferred because they grow almost twice as fast as the females. This paper reviews monosex male production techniques and their results, comprising environment manipulation, hybridization, sex reversal and genetic manipulation. The choice of a particular technique would depend on the legislation of each country. This review’s should help to select the appropriate technique depending on the market target and the commercial technology available.Keywords: Monosex production, hybridization, sex reversal, environmental and genetic sex determinationAfrican Journal of Biotechnology Vol. 12(36), pp. 5496-550

Long-Range Wireless Mesh Network for Weather Monitoring in Unfriendly Geographic Conditions

In this paper a long-range wireless mesh network system is presented. It consists of three main parts: Remote Terminal Units (RTUs), Base Terminal Units (BTUs) and a Central Server (CS). The RTUs share a wireless network transmitting in the industrial, scientific and medical applications ISM band, which reaches up to 64 Km in a single point-to-point communication. A BTU controls the traffic within the network and has as its main task interconnecting it to a Ku-band satellite link using an embedded microcontroller-based gateway. Collected data is stored in a CS and presented to the final user in a numerical and a graphical form in a web portal

A Survey of Hybridisation Methods of GNSS and wireless LAN based Positioning System

Self-localisation has become a matter of course in our daily life. The emerging market of mobile devices still boosts the demand for seamless, ubiquitous positioning. The repertoire of sensors serviceable for localisation provided by current mobile devices is large; however the main positioning systems used today are based on wireless local area networks (WLAN), cellular networks and certainly global navigation satellite systems (GNSS). Because of the accuracy, the vast deployment and the channel characteristics, researchers have been focused on WLAN based positioning systems (WPS) in particular, to achieve seamless positioning. This paper reviews the latest data fusion approaches to seamless positioning by GNSS and WPS. In accordance to the level of data fusion, several approaches are categorised and briefly presented, differences in performance of these approaches are highlighted and future challenges identified.publishedVersionPeer reviewe

A New Method for Total Fat Detection in Raw Milk Based on Dual Low-Coherence Interferometer

The present work experimentally demonstrates a multimode fiber optic sensing setup for total fat detection in raw milk samples. The optical fiber arrangement incorporates a low-coherence Fabry–Perot cavity operating in dual response. The system provides a phase modulation for a total fat range from 0.97 to 4.36%. Here, the protein remains constant at ≈3%. The data indicate that maximum sensitivity close to 616 pm/%fat could be achieved at optimal wavelength operation (500 nm). In addition, the system presented a minimal repeatability error measurement of 0.08%, cross-sensitivity between protein and fat of 0.134, and a regression coefficient of r 2 = 0.9763 . A thermal analysis was also performed, which indicate the temperature immunity of the system. The proposed method represents a low-cost alternative to detect minimal fat variations in raw cow milk

Isolation and Characterization of Plant Growth-Promoting Compost Bacteria That Improved Physiological Characteristics in Tomato and Lettuce Seedlings

Currently, agricultural systems are inadequate to meet the demand of the population, coupled with the constant degradation of natural resources. Therefore, it is necessary to explore alternatives to increase the productivity and quality of crops with minimal environmental impact. The use of plant growth-promoting bacteria can provide solutions to some agri-environmental problems and replace or minimize conventional agricultural practices. In this study, a Bacillus pumilus strain with plant growth-promoting properties was isolated from mature compost. In vitro, the ability of Bacillus pumilus to solubilize phosphate, inhibit the growth of phytopathogenic fungi, and its effect on the germination of tomato and lettuce seeds was evaluated. In vivo, its effect on stem thickness, height, and the number of leaves of tomato and lettuce seedlings was studied. The results show that, in vitro, Bacillus pumilus solubilizes phosphate, inhibits the growth of the fungus Fusarium oxysporum, and increases the germination percentage of tomato seeds. The results, in vivo, demonstrate that the bacteria increases the stem thickness of tomato seedlings, while, in lettuce, it increases the stem thickness and the number of leaves. The outcome implies that Bacillus pumilus has properties as a plant growth promoter and can be used as a promising inoculant to enhance the growth of tomato and lettuce seedlings

Optical Methods Based on Ultraviolet, Visible, and Near-Infrared Spectra to Estimate Fat and Protein in Raw Milk: A Review

The present manuscript focuses on reviewing the optical techniques proposed to monitor milk quality in dairy farms to increase productivity and reduce costs. As is well known, the quality is linked to the fat and protein concentration; in addition, this issue is crucial to maintaining a healthy herd and preventing illnesses such as mastitis and ketosis. Usually, the quality of the milk is carried out with invasive methods employing chemical reagents that increase the time analysis. As a solution, several spectroscopy optical methods have been proposed, here, the benefits such as non-invasive measurement, online implementation, rapid estimation, and cost-effective execution. The most attractive optical methods to estimate fat and protein in cow’s milk are compared and discussed considering their performance. The analysis is divided considering the wavelength operation (ultraviolet, visible, and infrared). Moreover, the weaknesses and strengths of the methods are fully analyzed. Finally, we provide the trends and a recent technique based on spectroscopy in the visible wavelength

Revaluation of Local Waste through an Ecotechnologies Strategic Plan: A Case Study with Digesters

In Mexico, the accelerated and unplanned growth of population causes the increment in informal facilities, complicating access to essential services such as adequate sanitation and organic waste management, where the most affected are usually the vulnerable population. The Mexican government has implemented programs and support to encourage the use of ecotechnologies and thus provide alternatives to improve their living conditions by taking advantage of local resources and waste. However, these programs and supports lack planning, creating little interest from users. This research proposes an acceptance strategy for the integration of ecotechnologies that adapt to the lifestyle of populations that need an alternative for their method of sanitation and organic waste management. The strategy is mainly based on a course of action that operates with four main lines of intervention. It was executed as a practical exercise with biodigesters, in the Mexican community of La Trinidad, in the municipality of Tequisquiapan, Querétaro. With the help of the strategy, important factors for the end-user were identified that must be considered when integrating one ecotechnology into the population. In general terms, the strategy showed an improvement in sanitation and organic waste management and a greater acceptance of biodigesters as an alternative of use

Revaluation of Local Waste through an Ecotechnologies Strategic Plan: A Case Study with Digesters

In Mexico, the accelerated and unplanned growth of population causes the increment in informal facilities, complicating access to essential services such as adequate sanitation and organic waste management, where the most affected are usually the vulnerable population. The Mexican government has implemented programs and support to encourage the use of ecotechnologies and thus provide alternatives to improve their living conditions by taking advantage of local resources and waste. However, these programs and supports lack planning, creating little interest from users. This research proposes an acceptance strategy for the integration of ecotechnologies that adapt to the lifestyle of populations that need an alternative for their method of sanitation and organic waste management. The strategy is mainly based on a course of action that operates with four main lines of intervention. It was executed as a practical exercise with biodigesters, in the Mexican community of La Trinidad, in the municipality of Tequisquiapan, Querétaro. With the help of the strategy, important factors for the end-user were identified that must be considered when integrating one ecotechnology into the population. In general terms, the strategy showed an improvement in sanitation and organic waste management and a greater acceptance of biodigesters as an alternative of use