Historical evidence of abrupt coastal climatic change in Southern California, 1790-1880

Historical sources of the late-18th and 19th centuries were searched for information on coastal weather conditions in Southern California. Relatively calm winters until 1828 were followed by unusually stormy winters from about 1829 to 1839. Later periods were again predominantly calm, with notable exceptions related to the ENSO events of 1845 and 1878. Following decreases through the stormy 1830s, sizes of kelp forests appear to have rebounded in the 1840s. ENSO occurrences and eruption of the volcano Cosiguina in 1835 are likely causes for changing wind patterns. Our results link the unique AD 1840 Macoma leptonoidea pelecypod shell layer in laminated Santa Barbara Basin sediment ("Macoma event") to abruptly changing oceanographic and weather patterns.

High productivity and upwelling in the California Current during Oxygen-Isotope Stage 3: diatom evidence

Evidence for vigorous coastal upwelling and enhanced diatom productivity during the latter part of Oxygen-Isotope Stage 3 (OIS-3) is suggested by changes in diatom assemblages in laminated sediment from the northern California margin and in bioturbated and laminated sediment from Santa Barbara Basin. These conditions require strong along-shore or off-shore wind stress off California preceding the onset of global glacial conditions.

Variability in a radiolarian time series and its relationship to climate

EXTRACT (SEE PDF FOR FULL ABSTRACT): Recently, paleoceanographers have been challenged to produce reliable proxies of climate variables that can be incorporated into climate models. In developing proxies using time series of annual radiolarian species fluxes from Santa Barbara Basin, we identify groups of species associated with years of extreme sea surface temperatures and sea level heights.

Evidence for changes in large-scale upwelling in the California Current over the past 700 years [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Bidecadal radiocarbon measurements on tree rings provide a detailed series of carbon-14 activities at isotopic equilibrium with atmospheric carbon dioxide. ... Most marine environments do not permit development of a comparable series of carbon-14 ages with which to compare the terrestrial tree ring series. However, we have recently begun work on such a series using material from the varved sediments of the Santa Barbara Basin off southern California. ... We now have a nearly continuous record of carbon-14 dates representing the age of the water over the upper 100 meters. ... The ocean reservoir ages show an increase prior to 1450 and a progressive decrease with time after 1450. Although there may be other explanations, we believe this trend is principally the result of changes in large-scale upwelling of water from below 500 meters. These changes were probably also associated with changes in the intensity of the California Current.

Integrating varve and tree-ring time series for southern California climate reconstruction: a 20th century outlook [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Our objective is to combine terrestrial and oceanic records for reconstructing West Coast climate. Tree rings and marine laminated sediments provide high-resolution, accurately dated proxy data on the variability of climate and on the productivity of the ocean and have been used to reconstruct precipitation, temperature, sea level pressure, primary productivity, and other large-scale parameters. We present here the latest Santa Barbara basin varve chronology for the twentieth century as well as a newly developed tree-ring chronology for Torrey pine.

The near-AD 1600 multi-proxy puzzle

EXTRACT (SEE PDF FOR FULL ABSTRACT): A varve chronology with annual resolution (AD 1117-1992) has been developed recently for Santa Barbara Basin. Varve thickness and water content show an exponential trend consistent with expected patterns in the presence of sediment compaction over time. Annual varve thickness was decomposed into orthogonal components using singular spectrum analysis (SSA) to identify and retrieve inter-decadal oscillations. ... This suggests a connection with global-scale decadal cycles identified in the subtropical Pacific gyre circulation and, possibly, with solar-driven phenomena. The near-1600 AD event coincides with (a) a similarly sudden change of state in nearby Santa Monica Basin that triggered the onset of anoxic conditions and the preservation of laminated sediments, (b) an extreme drought over the American Southwest, (c) a transformation of the age structure in a number of forest populations throughout Arizona and New Mexico. Total organic carbon burial flux in Santa Barbara Basin varves also shows a marked change after AD 1600. A possible climatic link is proposed that involves pathways for moisture transport in the Southwest at decadal and longer time scales.

Preliminary evaluation of a nuclear scenario involving innovative gas cooled reactors

In order to guarantee a sustainable supply of future energy demand without compromising the environment, some actions for a substantial reduction of CO 2 emissions are nowadays deeply analysed. One of them is the improvement of the nuclear energy use. In this framework, innovative gas-cooled reactors (both thermal and fast) seem to be very attractive from the electricity production point of view and for the potential industrial use along the high temperature processes (e.g., H 2 production by steam reforming or I-S process). This work focuses on a preliminary (and conservative) evaluation of possible advantages that a symbiotic cycle (EPR-PBMR-GCFR) could entail, with special regard to the reduction of the HLW inventory and the optimization of the exploitation of the fuel resources. The comparison between the symbiotic cycle chosen and the reference one (once-through scenario, i.e., EPR-SNF directly disposed) shows a reduction of the time needed to reach a fixed reference level from ∼170000 years to ∼1550 years (comparable with typical human times and for this reason more acceptable by the public opinion). In addition, this cycle enables to have a more efficient use of resources involved: the total electric energy produced becomes equal to ∼630 TWh/year (instead of only ∼530 TWh/year using only EPR) without consuming additional raw materials. © 2009 Barbara Vezzoni et al.

Abundance and conservation status of the Yangtze finless porpoise in the Yangtze River, China

middle and lower reaches of the Yangtze River, China. It is the only freshwater population of porpoises in the world and is currently listed as Endangered by IUCN. In November and December 2006 we used two boats and line transect methods to survey the entire current range of the population, except for two lakes (Poyang and Dongting). Sighting results were similar for both boats, so we pooled all data and analyzed them using two line transect models and a strip transect model. All models produced similar estimates of abundance (1111, 1225 and 1000). We then added independent estimates of the number of porpoises from the two lakes for a total estimate of approximately 1800 porpoises. Our findings indicate that the population continues to decline and that its distribution is becoming more fragmented. Our current estimate in the main river is slightly less than half the estimate from surveys between 1984 and 1991 (which was probably an underestimate). We also found an apparent gap in the distribution of porpoises between Yueyang and Shishou (similar to 150 km), where sightings had previously been common. Continued threats to Yangtze finless porpoises include bycatch in unregulated and unselective fishing, habitat degradation through dredging, pollution and noise, vessel strikes and water development. Immediate protective measures are urgently needed to ensure the persistence of finless porpoises in the Yangtze River. The survey design and analytical methods developed in this study might be appropriate for surveys of cetaceans in other river systems. (c) 2008 Elsevier Ltd. All rights reserved.

First human-caused extinction of a cetacean species?

The Yangtze River dolphin or baiji ( Lipotes vexillifer), an obligate freshwater odontocete known only from the middle-lower Yangtze River system and neighbouring Qiantang River in eastern China, has long been recognized as one of the world's rarest and most threatened mammal species. The status of the baiji has not been investigated since the late 1990s, when the surviving population was estimated to be as low as 13 individuals. An intensive six-week multivessel visual and acoustic survey carried out in November-December 2006, covering the entire historical range of the baiji in the main Yangtze channel, failed to find any evidence that the species survives. We are forced to conclude that the baiji is now likely to be extinct, probably due to unsustainable by-catch in local fisheries. This represents the first global extinction of a large vertebrate for over 50 years, only the fourth disappearance of an entire mammal family since AD 1500, and the first cetacean species to be driven to extinction by human activity. Immediate and extreme measures may be necessary to prevent the extinction of other endangered cetaceans, including the sympatric Yangtze finless porpoise ( Neophocaena phocaenoides asiaeorientalis).

A new enzyme immunoassay for PCDD/F TEQ screening in environmental samples: Comparison to micro-EROD assay and to chemical analysis

A new Enzyme ImmunoAssay (EIA) for PCDD/F TEQ measurement in extracts of environmental samples was described. The bioassay TEQ which derived from EIA and EROD were compared with each other and with results from chemical analysis. For all environmental samples, the EROD-TEQ is higher than the value from chemical analysis. However, the EIA-TEQ is much more identical with the value from chemical analysis. Our results indicate that the EIA assay is a complementary method to the EROD assay and should be useful as a rapid and sensitive screening tool for environmental samples in many situations. (C) 1999 Elsevier Science Ltd. All rights reserved

Stratigraphic Model Predictions of Geoacoustic Properties

Geoacoustic properties of the seabed have a controlling role in the propagation and reverberation of sound in shallow-water environments. Several techniques are available to quantify the important properties but are usually unable to adequately sample the region of interest. In this paper, we explore the potential for obtaining geotechnical properties from a process-based stratigraphic model. Grain-size predictions from the stratigraphic model are combined with two acoustic models to estimate sound speed with distance across the New Jersey continental shelf and with depth below the seabed. Model predictions are compared to two independent sets of data: 1) Surficial sound speeds obtained through direct measurement using in situ compressional wave probes, and 2) sound speed as a function of depth obtained through inversion of seabed reflection measurements. In water depths less than 100 m, the model predictions produce a trend of decreasing grain-size and sound speed with increasing water depth as similarly observed in the measured surficial data. In water depths between 100 and 130 m, the model predictions exhibit an increase in sound speed that was not observed in the measured surficial data. A closer comparison indicates that the grain-sizes predicted for the surficial sediments are generally too small producing sound speeds that are too slow. The predicted sound speeds also tend to be too slow for sediments 0.5-20 m below the seabed in water depths greater than 100 m. However, in water depths less than 100 m, the sound speeds between 0.5-20-m subbottom depth are generally too fast. There are several reasons for the discrepancies including the stratigraphic model was limited to two dimensions, the model was unable to simulate biologic processes responsible for the high sound-speed shell material common in the model area, and incomplete geological records necessary to accurately predict grain-size

The direct electrochemistry behavior of Cyt c on the modified glassy carbon electrode by SBA-15 with a high-redox potential

It is discovered that SBA-15 (santa barbara amorphous) can provide the favorable microenvironments and optimal direct electron-transfer tunnels (DETT) of immobilizing cytochrome c (Cyt c) by the preferred orientation on it. A high-redox potential (254 mV vs. Ag/AgCl) was obtained on glassy carbon (GC) electrode modified by immobilizing Cyt c on rod-like SBA-15. With ultraviolet-visible (UV-vis), circular dichroism (CD), FTIR and cyclic voltammetry, it was demonstrated that immobilization made Cyt c exhibits stable and ideal electrochemical characteristics while the biological activity of immobilized Cyt c is retained as usual.

贵州赫章土法炼锌地区重金属对植物污染的初步研究

矿山开发造成的生态环境问题是一个世界性的问题，国内外许多学者对此表现出浓厚的兴趣。除矿山开发直接导致的植被破坏和耕地侵蚀等外，研究者更重视有害物质(特别是重金属)释放而导致的环境问题，特别是表生条件下矿山废弃物(矿山尾砂)的堆积，在一系列地球化学因素的作用下：如矿山尾砂的矿物成分 参考、堆积时间、厚度、气候条件及微生物（Rachel，2002）等发生风化作用，从而导致酸性矿山废水(AMD)的产生。蓄纳高浓度的重金属元素，其排放小仅对溪流、河流、湖泊水质及其沉积物产生负而影响，而且有降低土壤环境质量状况的威胁（Barbara Hohn，2005）。 贵州省赫章县是我国著名的土法炼锌集散地，地处贵州西北部，辖内煤炭资源丰富，境内的榨子厂、猫猫厂、天桥铅、锌矿(氧化矿)为“土法炼锌”提供了丰富的原料。其土法炼锌已有300多年的历史，至2000年，已有1000多个土法炼锌“马槽炉”的规模。炼锌中产生的黑色烟尘不仅使周围山坡寸草不生，山坡上、河道边到处倾倒着废渣，而且使许多早作地荒耕。本文试图以该地的土法炼锌为研究对象，探讨土法炼锌中产生的烟尘和废弃物对附近土壤和沉积物的环境影响。 1.1矿山开发中的生态环境影响 矿山的开采在很大程度上改变了矿山原有的环境。矿山开采耗费大量的土地资源，开采后破坏的土地，丧失原有的自然生态系统；废弃物堆置场是周围环境的严重污染源。矿山按其产品性质分类，有冶金矿山(黑色金属、有色金属、稀土元素、放射性元素等)和非金属矿山(煤矿、石料、陶土等)；按其开采方式分类，有露天开采矿山和地下开采矿山。不同性质的矿山和不同的开采方式，其对生态环境破坏的过程和特征有很大差异。 矿山开采引起的生态破坏，主要由以下三个过程导致：(1)开采活动对土地的直接破坏，如露天开采会直接毁坏地表土层和植被，地下开采会导致地层塌陷，从而引起土地和植被的破坏：(2)矿山开采过程中的废弃物(如尾矿、矸石等) 需要大面积的堆置场地，从而导致大量占用土地和对堆置场原有生态系统的破坏；(3)矿山废弃物中的毒性成分，可通过径流和大气飘尘，影响周围的土地、水域和大气质量（Ivanova，2001）。 在生态系统层次上，上述三个过程对采矿地区生态的破坏具有三个特征：(1)景观破坏，主要指对地貌的影响；(2)环境质量退化，对所在地区土质、水质，甚至大气质量的影响；(3)生物多样性退化，对原有生物群落的摧毁，及对当地现有生物群落的严重破坏甚至摧毁。 通常，金属矿山引起的环境质量退化以及由此导致的生物多样性退化要比非金属矿山更严重；露天开采的矿山引起的景观破坏和生物多样性退化，要比地下开采的矿山更严重。矿山开发的生态环境影响突出表现在以下几下方面： 1土地的占用与破坏 矿山开采后，将会产出大量的废石、排土和尾砂，例如露天开采1吨矿石通常削离5-10 t覆盖的岩土，堆存它们将需占用大量的土地。据报道美国的明尼苏达州北部，由于大型露天磁铁矿近半世纪的大量开采，致使当地土壤质地退化，如不进行有效的治理将有沙漠化的危险（Othman，1996）。矿区的建设也将不可避免地改变地形、自然景观和植被状况等。土地破坏的后果是：水土流失加剧，淤塞污染水体，增加扬尘，严重影响生态环境。另外，尾矿坝、废石堆场设置不当或管理不严，会造成严重的滑坡或泥石流事故，使大面积的土地受到破坏，造成水体污染，危及人身和财产的安全。 2水体污染 矿山开采后的废石堆成尾矿库若不妥善处理，可能会成为地下水污染源。废矿堆、尾矿库长期处在氧化、风蚀、溶滤过程中，其中的有毒矿物成份或有害物质可以随水转入地下、地表水体和农田、土壤之中，造成地下、地表水体受到化学污染。 采矿工业用水远远小于选矿工业的用水量，但不论是采矿还是选矿，若不注意处理其废水，会造成严重的后果。据报道，由于采矿对水体的污染，使美国长达20600km的水域和449个天然和人工湖泊不再适于养鱼（Antonio Simonetti，2000）；在国内也不乏其例，如攀枝花选矿厂（曾清如，1997）有部分尾矿废水排入金沙江，对其造成长期的严重污染。又如东鞍山矿（张宝贵，2002）由于外排废水中含有大量的细粒级悬浮物，使杨柳河的河水呈红色，不仅妨碍水生生物的生长，还影响农业灌溉，成为鞍山地区的一大公害。此外开采硫化矿床时，由于伴生的低品位黄铁矿，在自然堆放过程中，经风化、雨水浸蚀可产生有害酸性水。在我国冶金矿山中因酸性水污染造成的危害是十分严重的，如南山铁矿（许步信，1996）的酸性水波及周围1万hm2农田和渔业生产，多年来共赔偿农业损失费累计约百万元。此外，各金属矿山的外排水中浮悬药剂的污染、硝基苯的污染以及其它重金属的污染也屡见不鲜（Sastre，2002）。 井巷开掘、矿床排水疏干所形成的降压漏斗的水力影响半径有时可达数十公里，可能造成区域性水文环境的破坏，使农牧业缺水受损。另外，疏干碳酸盐围岩含水层之后，其岩溶和溶洞会成为地面塌陷下沉，地面设施被破坏的隐患；而当塌陷区或井巷地表贮水体存在水力的沟通时，则会酿成淹没矿井的重大事故；当岩层疏干影响的设计计划不周时，还可导致露天边坡、台阶的滑动和变形，从而出现相应的灾害后果（李小玉，2004） 3大气污染 在矿山生产中，氧化、风蚀作用可使废石堆场、尾矿库形成一个周期性的尘暴源。此外矿石破碎、筛分和选矿等工序也是主要尘源。矿山对大气的污染还包括公路运输过程中形成的大量扬尘。粉尘污染是冶金矿山生产过程中的一种主要污染类型。在我国，由于矿山粉尘污染而使矿区农牧业受害的情况较多。矿山开发引起的环境生态问题是全球性的问题，越来越受到科学界的关注，己成为环境地球化学研究的一个重要领域。随着对矿产资源需求的不断扩大，矿山废物的排放量大幅度增加，环境生态的恢复难度也在不断增大，因此，在科学界关注的同时，政府也要采取一定的措施来给予支持和提供方便（王文，2003）。 1.2矿区重金属污染研究 1.2.1重金属概念及环境化学行为 通常把密度大于5的金属称为重金属，如隔、铬、铜、镍、铅、锌等，砷虽然不属于金属，但由于对环境的影响与重金属类似，通常也称其为重金属。矿产开采过程中所引起的环境问题较多，特别是土壤的重金属污染（Ahmed，1998）。有害重金属通过各种途径进入土壤，不易随水淋溶，微生物难以降解，植物对其有明显的生物富集作用，影响农作物的品质和产量。土壤污染有较长的潜伏期，具有隐蔽性、不可逆性、普遍性、表聚性等特征（Isabelle，2001） 重金属是一类典型的环境污染物，在自然条件下，除了局部范围重金属含量较高之外，一般土壤中有害重金属含量都小于构成污染的临界值。由于受人类生产活动的影响，例如，农业增产措施如农药、化肥的不断使用，加之工业废水、废气、城市生活垃圾、污水及污泥与畜禽粪便等排入环境，都不断污染土壤，使重金属等在环境中的积累不断积聚。特别是最近几十年来，由于土壤环境中污染物含量不断提高，重金属污染问题已经引起学术界、政府和公众的广泛关注。 1.2.2环境中重金属的来源 重金属可以通过废水、废渣的排放，空气悬浮物的携带与运输，水体中的细微尾矿砂颗粒物的运移，食物链的传递等不同途径来引起环境的污染。污染源有以下几个方面： 工业污染源，尤其是基础工业，特别是采矿和冶炼业是向环境中释放重金属的主要污染源。如20世纪60年代，在日本的富山县神通川流域，由于铅锌冶炼厂排放的含锅废水污染水稻田，居民长期食用含偏稻米和饮用含锅水而造成锅中毒，锅进入人体后破坏人体的骨骼系统，使骨质变脆易折，也就是所谓的“骨痛病（Lorenzo，2000）。 生活污染源，主要是生活垃圾，其中含有的重金属能渗到土壤中，影响到地表水和地下水的质量，生活废水中的有机物可以吸收重金属，用这些水灌溉也可导致土壤污染。 农业污染源，主要来自厩肥、污泥、化肥、农药等，有害成分为其释放的重金属，污染物质主要集中于表层或耕层，它的分布比较广泛。污染物的种类和污染的轻重程度与土地的利用方式和耕作制度有关。 交通污染源，主要为含铅汽油的使用，使机动车排放的尾气污染大气。 自然污染源，土壤母质中的重金属本身含量高，还有火山喷发造成的土壤污染。 就矿区来说，以工业污染源为主，其它次之。 1.2.3环境中重金属的危害 尾矿、矿渣是采矿区土壤重金属的主要来源之一。当这些矿山固体垃圾从地下搬运到地表后，由于所处环境的改变，在自然条件下，极易发生风化作用(物理、化学和生物作用)，使大量有毒有害的重金属元素释放出来进入到土壤和水体中，给采矿区及周围环境带来严重的污染。 在雨水等的作用下，地下水和地表水都会受到不同程度的重金属污染。目前世界上受高砷饮水危害的国家和地区包括孟加拉国、印度恒河流域、阿根廷、智利、墨西哥、泰国、美国和中国的台湾、内蒙、山西部分地区。孟加拉国受砷危害人口有35-77百万人，占该国总人口(125百万)的一大半，几十年来联合国投入了大量财力物力进行治理，但收效甚微（Kovalchuk，1996）。有300多年开采历史的我国湖南石门雄黄矿，发生了严重的砷污染，河水砷含量达0.5－14.5 mg•L－1，居民头发砷含量为0.972-2.459ug•L-1。以河水为饮用水源的居民的砷暴露水平达到甚至超过国内外重大慢性砷中毒案例的暴露水平。 有毒气体的排放无疑会直接污染大气。如1996年玻利维亚波托西的波尔科矿山的一座铅锌尾矿坝倒塌，致使大约235，000 t有毒尾矿泥浆(包括砷、氰化物、铅和锌等有害成分)排入皮科马约河的一条支流阿瓜卡斯蒂利亚河中，导致饮用该河水和食用该河水中鱼的3名儿童死亡，其毒性影响到800km的巴拉圭一阿根廷的查科(salomons，1995)。另外，巴西亚马逊河流域附近，约17000km，的大范围金矿开采过程中，汞作为重要提金试剂，易形成合金金齐汞，直接释放进入大气，且向大气的释放量远比向河流和土壤的释放量高，占总释放量的65%-83%( salomons，1995)，对人体危害十分严重。西班牙某重金属冶炼厂尾砂坝的倒塌，使得随后的土地开发过程中大气可吸入颗粒中铜和锰的含量增加了17~36％和59一70％（Querol，2000）。 重金属在土壤中的聚集引起的危害更为严重。其进入土壤后，一方面可在植物体中累积，并通过食物链最终转移到人体内，危害人群健康，致畸致癌；另一方面，还可能导致地下水污染，超过一定限度就会危害生态系统，如上述所说的水体和大气的污染。由于重金属污染的范围广，持续时间长，又不易在生物物质循环和能量交换中分解，所以污染土壤的修复与治理迫在眉睫，也是科学界比较关注的问题之一。就世界范围来看，全世界每年平均排放汞115万t，锰1500万t，铜340万t，铅500万t，镍100万（Jane vacalet，1999）。据估计，我国仅重金属污染的耕地面积就达2000万ha，约占耕地总面积的115 ，每年因土壤污染而减产粮食1000万t；另外还有1200万t粮食重金属超标，二者的直接经济损失达200多亿元（陈同斌，1999）。在金属成矿区周围的自然扩散区域内，环境中一般含有较高浓度的重金属，加上开矿过程中的废矿水和尾矿砂，常造成严重的重金属污染问题。据报道，湖南省郴县东坡铅锌矿自然扩散晕区域内的环境污染是以铅、锌、镉、砷为主的多金属污染复合体，水体内的细微尾矿砂颗粒物是重金属的主要迁移载体，且该区域内作物中的铅、镉残留很高（曾清如，1994）。 土壤中重金属的超标同时也会使农作物和其它生物受到危害。杨居荣（1992）发现耐福的甜菜与胡萝卜在对营养元素的吸收上呈现两种不同的特征，即耐镐的甜菜往往对钙、镁、锌、铁元素的吸收量大，而胡萝卜则相反。土壤中锌/锅比例增大可显著地降低菠菜含镉量（宋菲，1996）。己有证据表明，铜矿的冶炼可以增加周围农业系统中的铜含量，使冶炼厂周围紫花首稽和柏树叶片中的铜含量明显增加。华南某矿区周围农田土壤中锌含量达690~4000 mg.kg－1；华北某污灌区土壤中锌含量超过1500 mg•kg－1，长期施用污泥的土壤中锌含量达370－470 mg•kg－1，受汞污染的面积达3.2 × 104 ha，每年生产汞米1.95×105吨。沈阳张士灌区和江西大余县等地区的粮食己经遭受严重的锡污染，其含镉量己经超过诱发“痛痛病”的标准。龙育堂等（1994）研究芝麻对稻田汞净化效果，结果表明：土壤含汞量在5－130 mg•kg－1，范围内，汞对芝麻产量和品质仍未造成显著影响；改种芝麻，土壤汞的年净化率高达41%，土壤的自净恢复年限比种植水稻缩短。食物链中重金属的高度富集最终将威胁到人类健康。

Designing Computer Games to Facilitate Learning

The aim of this thesis was to explore the design of interactive computer learning environments. The particular learning domain selected was Newtonian dynamics. Newtonian dynamics was chosen because it is an important area of physics with which many students have difficulty and because controlling Newtonian motion takes advantage of the computer's graphics and interactive capabilities. The learning environment involved games which simulated the motion of a spaceship on a display screen. The purpose of the games was to focus the students' attention on various aspects of the implications of Newton's laws.

An Accountable Source-To-Source Transformation System

Though one is led to believe that program transformation systems which perform source-to-source transformations enable the user to understand and appreciate the resulting source program, this is not always the case. Transformations are capable of behaving and/or interacting in unexpected ways. The user who is interested in understanding the whats, whys, wheres, and hows of the transformation process is left without tools for discovering them. I provide an initial step towards the solution of this problem in the form of an accountable source-to-source transformation system. It carefully records the information necessary to answer such questions, and provides mechanisms for the retrieval of this information. It is observed that though this accountable system allows the user access to relevant facts from which he may draw conclusions, further study is necessary to make the system capable of analyzing these facts itself.