山上的"大房子"姜乐静的"潭南国小"

这是台湾921地震(1999年)后重建民间捐助的代表性案例,坐落在日月潭南边高山偏远地区,建筑师以布农族"家屋"的转化来重建这一村落学习"机构",以"大房子"意象作为基本的建构形式,也形成村落重建的精神方舟.建筑师诚恳地让山本身来造就了这大房子.     

Origin of HIV-1 in the chimpanzee Pan troglodytes troglodytes

The human AIDS viruses human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) represent cross-species (zoonotic) infections. Although the primate reservoir of HIV-2 has been clearly identified as the sooty mangabey (Cercocebus atys), the origin of HIV-1 remains uncertain. Viruses related to HIV-1 have been isolated from the common chimpanzee (Pan troglodytes), but only three such SIVcpz infections have been documented, one of which involved a virus so divergent that it might represent a different primate lentiviral lineage. In a search for the HIV-1 reservoir, we have now sequenced the genome of a new SIVcpzstrain (SIVcpzUS) and have determined, by mitochondrial DNA analysis, the subspecies identity of all known SIVcpz-infected chimpanzees. We find that two chimpanzee subspecies in Africa, the central P. t. troglodytes and the eastern P. t. schweinfurthii, harbour SIVcpz and that their respective viruses form two highly divergent (but subspecies-specific) phylogenetic lineages. All HIV-1 strains known to infect man, including HIV-1 groups M, N and O, are closely related to just one of these SIVcpz lineages, that found in P. t. troglodytes. Moreover, we find that HIV-1 group N is a mosaic of SIVcpzUS- and HIV-1-related sequences, indicating an ancestral recombination event in a chimpanzee host. These results, together with the observation that the natural range of P. t. troglodytes coincides uniquely with areas of HIV-1 group M, N and O endemicity, indicate that P. t. troglodytes is the primary reservoir for HIV-1 and has been the source of at least three independent introductions of SIVcpz into the human population.     

电液比例控制技术在电解铜堆垛上的应用

采用电液比例控制技术对电解铜堆垛装置进行控制。分析了控制的工作原理及实现方法;探讨了系统的稳定性;采用PID校正技术对系统的稳定性进行校正。     

EFFECT OF ULTRASONIC TREATMENTS ON THERMOACIDOPHILIC ALICYCLOBACILLUS ACIDOTERRESTRIS IN APPLE JUICE

The effect of ultrasonic treatments on Alicyclobacillus acidoterrestris in apple juice was investigated. In general, inactivation of the cells was more pronounced at an elevated power level and as the processing time increased. Approximately 60% of the cells were inactivated after treating the apple juice with 300-W ultrasound for 30 min. The reduction reached more than 80% when the juice was processed for 60 min. The linear inactivation rates ( D values) of ultrasound on A. acidoterrestris were both process- and strain-dependent. The lowest D value at 36.18 min was found when using 600-W ultrasound to treat the A30 strain isolated from the air of a commercial apple juice processing plant, whereas the strain isolated from apple juice concentrate was found most resistant against ultrasound. Changes of sugar content, acidity, haze and juice browning were noted after ultrasonic treatments but did not adversely alter the juice quality.

PRACTICAL APPLICATIONS

Characterization of the effects of ultrasonic treatments on thermoacidophilic Alicyclobacillus acidoterrestris provides better understanding of how ultrasound technology could assist in alleviating the hard-to-detect spoilage caused by this spore former. Although ultrasonic technology might not be suitable as a standalone unit operation to inactivate high cell loads, the process could be integrated with other thermal or nonthermal technologies to enhance processing efficiencies, consequently preventing microbial spoilage caused by A. acidoterrestris .     

EFFECTS OF INTERMOLECULAR INTERACTIONS AND MOLECULAR ORIENTATION ON THE FLUX BEHAVIOR OF XANTHAN GUM SOLUTIONS DURING ULTRAFILTRATION

Conformational changes of xanthan gum as a function of concentration were investigated to elucidate its unusual flux behavior during ultrafiltration (UF). The contribution of hydrogen bonding on structure formation and the molecular orientation of xanthan gum on the flow characteristics were studied rheomechanically and rheo-optically. Known to affect xanthan structure at low concentrations, hydrogen bonding unexpectedly did not show significant influence on xanthan rheological properties up to 2 wt %. The ordered layers formed on the membrane surface proved responsible for the enhanced water removal during UF. This unique behavior could be attributed to the formation of aligned molecular orientation in addition to the viscosity increases during the biphasic region. Significant differences were observed between xanthan fermentation broth and solutions made of commercial xanthan, suggesting the need to control the salt concentration in fermentation broth in order to make UF an effective recovery process for xanthan gum after fermentation.

PRACTICAL APPLICATIONS

The knowledge gained from the present study strengthens fundamental understandings on the conformational changes of xanthan biopolymers during the recovery of xanthan gum from fermentation broth using ultrafiltration (UF). By taking advantage of the aligned molecular orientation, along with controlling the salt concentration in the fermentation broth, UF could be operated at elevated flux to speed up the removal of water from the viscous fermentation broth. The technology should find broad applications in the fermentation industry, especially where viscosity is of concern during the separation and purification of the product.     

The solid modelling of part orienting tracks for automated assembly

Part orienting tracks used for feeding component parts to an automated assembly system are conventionally designed and fabricated manually by increasingly small numbers of skilled operators. It is time-consuming, labour-intensive and hence results in expensive tooling cost and long manufacture lead time. A new approach based on solid modelling has been developed to facilitate efficient track design and manufacture

This paper presents the methodology adopted in the development and implementation of the CAD system. It describes the conceptual model of an orienting track, discusses the overall data structure of the system, and outlines the method used in modelling tracks. The paper concludes with an example demonstrating how an orienting track can be designed using the CAD system.     

FLOW PROPERTIES OF BABACO (CARICA PENTAGONA) PUREES AND CONCENTRATES

A power law model describes adequately the rheological behaviour of Babaco purees and concentrates while a Herschel-Bulkley model describes concentrates only. A single equation η_a=α x cβ x exp (E_a/RT), combining the effects of temperature and concentration on apparent viscosity (η_a100), was used to describe rheological behaviour.     

Advancements in non-starch polysaccharides research for frozen foods and microencapsulation of probiotics

Conventionally used in the food industry as stabilizing, thickening, gelling, and suspending or dispersing agents, non-starch polysaccharides such as xanthan gum are known to improve the texture of certain frozen products. Another polysaccharide that has received significant attention in recent years is chitosan, a natural biopolymer derived from chitin. In the wake of growing interest in finding ideal encapsulating agents for probiotics, non-starch polysaccharides have been investigated. Scattered research can be found on the effect of each individual polysaccharide, but there remains a void in the literature in terms of closely comparing the characteristics of non-starch polysaccharides for these applications, especially when more than one biopolymer is employed. A good understanding of the tools capable of elucidating the underlying mechanisms involved is essential in ushering further development of their applications. Therefore, it is this review’s intention to focus on the selection criteria of non-starch polysaccharides based on their rheological properties, resistance to harsh conditions, and ability to improve sensory quality. A variety of critical tools is also carefully examined with respect to the attainable information crucial to frozen food and microencapsulation applications.     

Formatted Spreadsheets for Engineers

Spreadsheets are powerful programs for personal computers, and in many respects they have a clear edge over established programming languages such as FORTRAN or BASIC for simple day-to-day engineering applications. Modern spreadsheets such as lotus 1–2-3(TM), Excel (TM), Symphony(TM), Jazz (TM), Quattro (TM), etc. are very easy to learn and they can be used for a multitude of tasks including desktop calculation, text editing, data base functions and graphics. The one decided advantage of spreadsheets is that they are totally interactive; a user can use spreadsheets directly without having to worry about data files and output files. The ideas explained in this paper are applicable to most commercially available spreadsheets with the particular examples shown applicable to Lotus 1–2-3. The technique of "formatted" worksheets has been developed and successfully used by the author in teaching and in his professional work for several years. A thorough knowledge of spreadsheets is imperative for the efficient application of this technique. Some practical ideas plus a set of macros will be shown.     

Structure and epitope characterisation of the O-specific polysaccharide of Proteus mirabilis O28 containing amides of D-galacturonic acid with L-serine and L-lysine

The O-specific polysaccharide of Proteus mirabilis O28 was found to contain D-galactose, D-galacturonic acid (GalA), 2-acetamido-2-deoxy-D-glucose, L-serine, L-lysine, and O-acetyl groups in molar ratios 1:2:1:1:1:1, the amino acids being linked via their alpha-amino group to the carboxyl group of GalA. The polysaccharide was studied using 1H- and 13C-NMR spectroscopy, including selective spin-decoupling, one-dimensional total correlation spectroscopy, two-dimensional homonuclear correlation spectroscopy (COSY), heteronuclear 13C,1H COSY, one-dimensional NOE, and two-dimensional rotating-frame NOE spectroscopy and partial acid hydrolysis followed by borohydride reduction, methylation, and GLC/MS analysis of the derived glycosyl alditols. The following structure of the repeating unit was established: [formula: see text] Epitope specificity of the P. mirabilis O28 polysaccharide was analysed using a homologous rabbit polyclonal antiserum in quantitative precipitation, passive immunohemolysis, and inhibition of passive immunohemolysis. Study with related synthetic glycopolymers (2-acrylamidoethyl glycosides of amides of alpha-D-GalA with amino acids copolymerised with acrylamide) showed the importance of D-GalA(L-Lys) for manifesting serological specificity of the O-antigen. Serological cross-reactions between P. mirabilis O28, S1959, and R14/S1959 (a transient-like form) are discussed.