An Evidence-based Review: Efficacy of Safety Helmets in the Reduction of Head Injuries in Recreational Skiers and Snowboarders

BACKGROUND: Approximately 600,000 ski- and snowboarding-related injuries occur in North America each year, with head injuries accounting for up to 20% of all injuries. Currently, there are no major institutional recommendations regarding helmet use for skiers and snowboaders in the United States, in part owing to previous conflicting evidence regarding their efficacy. The objective of this review was to evaluate existing evidence on the efficacy of safety helmets during skiing and snowboarding, particularly in regard to head injuries, neck and cervical spine injuries, and risk compensation behaviors. These data will then be used for potential recommendations regarding helmet use during alpine winter sports. METHODS: The PubMed, Cochrane Library, and EMBASE databases were searched using the search string helmet OR head protective devices AND (skiing OR snowboarding OR skier OR snowboarder) for articles on human participants of all ages published between January 1980 and April 2011. The search yielded 83, 0, and 96 results in PubMed, Cochrane Library, and EMBASE, respectively. Studies published in English describing the analysis of original data on helmet use in relation to outcomes of interest, including death, head injury, severity of head injury, neck or cervical spine injury, and risk compensation behavior, were selected. Sixteen published studies met a priori inclusion criteria and were reviewed in detail by authors. RESULTS: Level I recommendation is that all recreational skiers and snowboarders should wear safety helmets to reduce the incidence and severity of head injury during these sports. Level II recommendation/observation is that helmets do not seem to increase risk compensation behavior, neck injuries, or cervical spine injuries among skiers and snowboarders. Policies and interventions to increase helmet use should be promoted to reduce mortality and head injury among skiers and snowboarders. CONCLUSION: Safety helmets clearly decrease the risk and severity of head injuries in skiing and snowboarding and do not seem to increase the risk of neck injury, cervical spine injury, or risk compensation behavior. Helmets are strongly recommended during recreational skiing and snowboarding

Porosity development in activated carbon from palm kernel and coconut shell by chemical activation method

A preparation and modification of activated carbon from oil-palm shell has been investigated in this paper. A pretreatment method has been established to avoid partial fusion and swelling in the carbonization stage. Carbonization has been studied at different temperatures and the structure of the microporous chars has been characterized. Activated carbon has been prepared from steam gasification of chars obtained at 800O C. This activation increases both total and narrow microporosity and develops a substantial mesoporosity. Activated carbon with different pore size distribution is impregnated with zirconium chloride and iron chloride salts to give impregnated carbon with different metals loading. The presences of active metal on an impregnated activated carbon surface greatly affect the adsorption affinity since some inorganic compounds will then be adsorbed preferentially

Malware variant identification using incremental clustering

Dynamic analysis and pattern matching techniques are widely used in industry, and they provide a straightforward method for the identification of malware samples. Yara is a pattern matching technique that can use sandbox memory dumps for the identification of malware families. However, pattern matching techniques fail silently due to minor code variations, leading to unidentified malware samples. This paper presents a two-layered Malware Variant Identification using Incremental Clustering (MVIIC) process and proposes clustering of unidentified malware samples to enable the identification of malware variants and new malware families. The novel incremental clustering algorithm is used in the identification of new malware variants from the unidentified malware samples. This research shows that clustering can provide a higher level of performance than Yara rules, and that clustering is resistant to small changes introduced by malware variants. This paper proposes a hybrid approach, using Yara scanning to eliminate known malware, followed by clustering, acting in concert, to allow the identification of new malware variants. F1 score and V-Measure clustering metrics are used to evaluate our results

Porosity development in activated carbon from palm kernel and coconut shell by chemical activation method

Several series of activated carbons have been prepared by chemical activation with phosphoric acid from palm kernel and coconut shells to study the effect of preparation variables such as precursor, precursor size, pretreatment, impregnation condition and ratio and finally the carbonization temperature on specific surface area and pore distribution of the resulting active carbon. Both precursors showed similar N2 adsorption isotherms, an upward deviation at high relative pressure, revealing the presence of mesorpores when carbonized at 5000 C with H3PO4. The bigger hysteresis loop indicates higher mesoporosity in coconut shell derived carbon whereas palm kernel shell derived carbon showed a higher macroporosity nature Prolong sinking of the precursor in H3PO4 impregnation solution followed by carbonization at moderate temperature (450-500 0C) produces carbon of high surface area with a higher macroporosity. The lowering of precursor size favors micropore development and semi-drying of the impregnation chemical prior to carbonization diminishes the macroporosity to a great extent. Thus an appropriate choice of preparation variables enables us to produce high surface area of micro and mesoporous activated carbon

Porosity development in activated carbon from palm kernel and coconut shell by chemical activation method

Several series of activated carbons have been prepared by chemical activation with phosphoric acid from palm kernel and coconut shells to study the effect of preparation variables such as precursor, precursor size, pretreatment, impregnation condition and ratio and finally the carbonization temperature on specific surface area and pore distribution of the resulting active carbon. Both precursors showed similar N2 adsorption isotherms, an upward deviation at high relative pressure, revealing the presence of mesorpores when carbonized at 5000 C with H3PO4. The bigger hysteresis loop indicates higher mesoporosity in coconut shell derived carbon whereas palm kernel shell derived carbon showed a higher macroporosity nature Prolong sinking of the precursor in H3PO4 impregnation solution followed by carbonization at moderate temperature (450-500 0C) produces carbon of high surface area with a higher macroporosity. The lowering of precursor size favors micropore development and semi-drying of the impregnation chemical prior to carbonization diminishes the macroporosity to a great extent. Thus an appropriate choice of preparation variables enables us to produce high surface area of micro and mesoporous activated carbon

IFS on the multi-fuzzy fractal space.

The IFS is a scheme for describing and manipulating complex fractal attractors using simple mathematical models. More precisely, the most popular “fractal –based” algorithms for both representation and compression of computer images have involved some implementation of the method of Iterated Function Systems (IFS) on complete metric spaces. In this paper a new generalized space called Multi-Fuzzy Fractal Space was constructed. On these spases a distance function is defined, and its completeness is proved. The completeness property of this space ensures the existence of a fixed-point theorem for the family of continuous mappings. This theorem is the fundamental result on which the IFS methods are based and the fractals are built. The defined mappings are proved to satisfy some generalizations of the contraction condition

About fuzzy fixed point theorem in the generalized fuzzy fractal space.

The Banach fixed point theorem has applications in several branches of science. Many authors prove this theorem in different types of fuzzy metric spaces and fuzzy fractal spaces. The aim of this paper is to prove the Banach fixed point theorem in a new generalized space called multi fuzzy fractal space

Efficiency analysis for public key systems based on fractal functions.

In the last decade, dynamical systems were utilized to develop cryptosystems, which ushered the era of continuous value cryptography that transformed the practical region from finite field to real numbers. Approach: Taking the security threats and privacy issues into consideration, fractals functions were incorporated into public-key cryptosystem due to their complicated mathematical structure and deterministic nature that meet the cryptographic requirements. In this study we propose a new public key cryptosystem based on Iterated Function Systems (IFS). Results: In the proposed protocol, the attractor of the IFS is used to obtain public key from private one, which is then used with the attractor again to encrypt and decrypt the messages. By exchanging the generated public keys using one of the well known key exchange protocols, both parties can calculate a unique shared key. This is used as a number of iteration to generate the fractal attractor and mask the Hutchinson operator, so that, the known attacks will not work anymore. The algorithm is implemented and compared to the classical one, to verify its efficiency and security. We conclude that public key systems based on IFS transformation perform more efficiently than RSA cryptosystems in terms of key size and key space

The legal framework of the Islamic financial system : a study on the cases in Malaysia / Najahudin Lateh … [et al.]

The legal framework of the Islamic financial system in Malaysia is subjected to civil law. This is because the Federal Constitution which divides the jurisdiction of the civil and shari’ah matters is silent on whether the Shari’ah Court has the power to hear cases or disputes relating to Islamic finance. As such, numerous interpretations of the Civil Court in contractual and financial applications are given. Some of them conflict with the Shari’ah law and rather emphasise on the usage of the civil law. Henceforth, this study will be focusing on the results and interpretations of the Civil Court in cases of Islamic finance and banking. Furthermore, the authors recommend some amendments to the Constitution and relevant Acts, to strengthen the laws relating to Islamic finance and to enhance the role of the Shari’ah Court