bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Least Conjunctive Refinement and Promotion in the Refinement Calculus
Authors: Mahony Brendan P. 
Published: August 2002

Abstract.
A syntactic calculation of Morgan's least conjunctive refinement operator for predicate transformers is developed. The operator is used to develop a general approach to lifting relational operators to predicate transformer operators. Predicate transformer versions of the relational conjunction and disjunction operators are considered in detail. The Z-based technique of program promotion is considered in a refinement calculus setting. A standard Z promotion example is recast in the refinement calculus.
Revising Z: Part II – logical development
Authors: Henson Martin C. , Reeves Steve 
Published: August 2002

Abstract.

This is the second of two related papers. In “Revising Z: Part I - logic and semantics” (this journal) we introduced a simple specification logic Z

C

comprising a logic and a semantics (in ZF set theory). We then provided an interpretation for (a rational reconstruction of) the specification language Z within Z

C

. As a result we obtained a sound logic for Z, including the basic schema calculus. In this paper we extend the basic framework with more sophisticated features (including schema operations) and we mount a critique of a number of concepts used in Z. We further demonstrate that the complications and confusions which these concepts introduce can be avoided without compromising expressibility.
Parameterized Verification of Linear Networks using Automata as Invariants
Authors: Prasad Sistla A. , Gyuris Viktor 
Published: August 2002

Abstract.
The paper proposes an induction based approach, that employs automata as inductive invariants, for verifying safety and liveness properties of linear networks of arbitrary size. The proposed method has been shown to be complete for verifying safety properties. Automated methods that check for correcteness of such families of networks are proposed. These methods are based on generating an invariant automaton from the correctness property which is also specified by an automaton. These methods have been implemented and successfully tested on some examples.
Hybrid Verifications of Reactive Programs
Authors: Roux Olivier , Rusu Vlad , Cassez Franck 
Published: August 2002

Abstract.
We present in this paper some new language features and constructs, that allow the joint synchronous/asynchronous programming of reactive applications, as well as their formal verification.

We show that reactive applications may be dealt with from two points of view. First, from the
chronological
point of view, i.e., when reactions are instantaneous, generated by event occurrences in discrete time. Second, from the
chronometrical
point of view, when reactions have durations in dense time. This duality must be expressible in languages that allow a consistent programming of both
synchronous
and
asynchronous
features. The objective of mixing these dual approaches leads to model reactive systems by using
hybrid systems
, to deal simultaneously with both discrete and continuous phenomena. Furthermore, this must be followed by some verification of the application's properties, with respect to its behavioural and quantitative features.

We analyze several existing frameworks that meet these requirements, and propose our own approach based on the language E
lectre
.
Formalising a Value-Passing Calculus in HOL
Authors: Nesi Monica 
Published: August 2002

Abstract.
Milner's value-passing calculus for describing and reasoning about communicating systems is formalised in the HOL proof assistant. Based on a previously defined mechanisation of pure CCS (no data communication, only synchronisation) in HOL, value-passing agents are given behavioural semantics by translating them into pure agents. An interactive proof environment is derived that supports both reasoning about the value-passing calculus and verification of value-passing specifications, which are defined over an infinite value domain.
Social and Semiotic Analyses for Theorem Prover User Interface Design 1
Authors: Goguen Joseph 
Published: August 2002

Abstract.
We describe an approach to user interface design based on ideas from social science, narratology (the theory of stories), cognitive science, and a new area called algebraic semiotics. Social analysis helps to identify certain roles for users with their associated requirements, and suggests ways to make proofs more understandable, while algebraic semiotics, which combines semiotics with algebraic specification, provides rigorous theories for interface functionality and for a certain technical notion of quality. We apply these techniques to designing user interfaces for a distributed cooperative theorem proving system, whose main component is a website generation and proof assistance tool called Kumo. This interface integrates formal proving, proof browsing, animation, informal explanation, and online background tutorials, drawing on a richer than usual notion of proof. Experience with using the interface is reported, and some conclusions are drawn.
Hoare Logic and Auxiliary Variables
Authors: Kleymann Thomas 
Published: August 2002

Abstract.Auxiliary variables are essential for specifying programs in Hoare Logic. They are required to relate the value of variables in different states. However, the axioms and rules of Hoare Logic turn a blind eye to the role of auxiliary variables. We stipulate a new structural rule for adjusting auxiliary variables when strengthening preconditions and weakening postconditions. Courtesy of this new rule, Hoare Logic is adaptation complete, which benefits software re-use. This property is responsible for a number of improvements. Relative completeness follows uniformly from the Most General Formula property. Moreover, one can show that Hoare Logic subsumes Vienna Development Method's (VDM) operation decomposition rules in that every derivation in VDM can be naturally embedded in Hoare Logic. Furthermore, the new treatment leads to a significant simplification in the presentation for verification calculi dealing with more interesting features such as recursion.
Modelling and Validation: AUTOFOCUS and Quest
Authors: Slotosch Oscar 
Published: August 2002

Abstract.

We describe the graphical description techniques, their underlaying semantics and the validation techniques that have been applied to the FM99 example; furthermore we sketch the model and discuss the validation results we have obtained. A

UTO

F

OCUS

is the modelling tool, and the Quest environment connects the model to a broad spectrum of validation tools, including model checkers (SMV, SATO), theorem provers (VSE) and test tools (CTE). The original contribution, further publications, and A

UTO

F

OCUS

can be downloaded from http://autofocus.in.tum.de.
Intraoperative Iatrogenic Rupture of Hepatocellular Carcinoma
Authors: Liu Chi‐Leung , Fan Sheung‐Tat , Lo Chung‐Mau , Ng Irene Oi‐Lin , Poon Ronnie Tung‐Ping , Wong John 
Published: August 2002

Intraoperative iatrogenic rupture ofhepatocellular carcinoma (HCC), which can occur during hepaticresection when large tumors are being mobilized, may adversely affectthe operative outcome. Little information is available in theliterature on this serious intraoperative complication. The aim of thepresent study is to document iatrogenic rupture of HCC as a seriouscomplication during hepatic resection and its effects on the operativeand long‐term outcomes of patients with this complication. Aretrospective study was performed on all patients with intraoperativeiatrogenic rupture of HCC during hepatic resection from 1989 to 1997,and the operative and long‐term survival outcomes were compared withthose of patients without the complication. Among 194 patients whounderwent hepatic resection for a large HCC (? 5 cm) during the studyperiod, 8 (4.1%) had intraoperative iatrogenic rupture of the tumor.When compared with 186 patients with similar clinical parameters butwithout intraoperative rupture, patients with intraoperative rupturehad significantly more intraoperative blood loss (median 5.7 vs. 2.0 L;p = 0.01) and blood transfusion requirement (median3.1 vs 0.9 L; p = 0.02). On follow‐up, patients in theintraoperative rupture group had a significantly higher intraperitonealextrahepatic recurrence rate (33.3% vs. 2.9%; p =0.02) and significantly shorter survival (median 11.5 vs. 37.9 months,p = 0.04) when compared with patients without thecomplication. Intraoperative iatrogenic rupture is a seriouscomplication of hepatic resection for HCC because it is associated withincreased intraoperative blood loss, increased incidence ofintraperitoneal extrahepatic recurrence, and short survival. Extremecare should be taken during mobilization of the tumor, and analternative operative approach in the presence of a difficult hepaticresection of a large HCC may be required to avoid the complication.
Long‐Term Observation of Serum Thyroglobulin after Resection of Nontoxic Goiter and Relation to Ultrasonographically Demonstrated Relapse
Authors: Date John , Feldt‐Rasmussen Ulla , Blichert‐Toft Mogens , Hegedüs Lazlo , Graversen Hans P. 
Published: August 2002

AbstractThe object was to carry out a prospective study of the changes in serum thyroid hormones and thyroglobulin (Tg) following resection of nontoxic goiter and to investigate if there was a correlation to the pattern of relapse. A group of 39 consecutive patients, mainly with nodular, nontoxic goiter, were studied for 13 years following thyroidectomy. No thyroid hormone replacement therapy was given after surgery. The preoperative serum Tg level was elevated. After operation the mean serum Tg declined to a nadir of 43 μg/L at 1 year and subsequently increased to 90 μg/L at 10 years, with large individual differences. In 19 patients the serum Tg increased, in 1 it decreased, and in 19 no significant alteration was observed. Serum free thyroxine and triiodothyronine indices decreased following resection but achieved normal levels within 6 to 12 months. Serum thyroid‐stimulating hormone increased after resection, with a peak level 1 month after surgery, but it returned to normal levels at 1 year and remained stable for the rest of the period. At 13 years after resection the thyroid volume was determined by ultrasonography in 30 of the patients. In 10 patients the thyroid volume was enlarged (≥ 28 ml). In this group a rise of average serum Tg after resection [ΔTg(10‐1 year)] of 133 μg/L was observed, compared to 26 μg/L in the 20 patients without sonographic relapse (volume < 28 ml). A positive correlation was demonstrated between serum ΔTg(10‐1 year) postsurgically and thyroid volume 13 years after surgery. However, an overlap was observed between the groups with and without ultrasonographic relapse, probably in part due to large differences in the Tg synthesis activity of different follicle cell clones. It is concluded that repeated serum Tg determinations may provide biochemical evidence of increased growth activity of thyroid remnants monitored after goiter resection.
Laparoscopic Treatment of Nonparasitic Liver Cysts: Adequate Selection of Patients and Surgical Technique
Authors: Gigot J. F. , Legrand M. , Hubens G. , de Canniere L. , Wibin E. , Deweer F. , Druart M. L. , Bertrand C. , Devriendt H. , Droissart R. , Tugilimana M. , Hauters P. , Vereecken L. 
Published: August 2002

AbstractResults of laparoscopic fenestration in patients with a highly symptomatic solitary liver cyst (17 patients) or polycystic liver disease (PLD) (9 patients) were prospectively evaluated in a multicenter practice of general surgeons. Conversion to laparotomy was required in two patients because of inaccessible deep liver cyst in one and a diffuse form of PLD in the other. There was no mortality or major morbidity. Mean postoperative hospital stay was 4.6 days after successful laparoscopic procedures. During a mean follow‐up of 9 months, 23% of the patients had recurrence of symptoms and 38% had radiographic reappearance of cysts. Factors predicting failure included previous surgical treatment, deep‐sited cysts, incomplete deroofing technique, location in the right posterior segments of the liver, and a diffuse form of PLD with small cysts. Adequate selection of patients and type of cystic liver disease and meticulous and aggressive surgical technique are recommended.
Impact of lymph node metastasis on survival with early gastric cancer
Authors: Seto Yasuyuki , Nagawa Hirokazu , Muto Tetsuichiro 
Published: August 2002

AbstractThe impact of lymph node metastasis on the survival of early gastric cancer (EGC) cases remains controversial. A retrospective study of 621 patients with EGC undergoing gastrectomy with lymphadenectomy during the period 1966–1993 was performed to evaluate the influence of node involvement on long‐term outcomes. Lymph node metastasis was observed in 63 cases (10.1%). Two groups, EGC with and without node involvement, were compared with respect to long‐term results and various clinicopathologic factors. The median observation period was 123 months. EGC cases without metastatic nodes had significantly better outcomes than those with node involvement in terms of overall survival as well as survival excluding deaths due to diseases unrelated to the primary EGC. Survival rates for EGC patients with node involvement did not, however, differ significantly according to the number of metastatic nodes. Three factors‐submucosal invasion, large tumor size, and recurrence‐were significantly related to lymph node metastasis. Age, sex, family history of malignancy, histologic type, and multiple occurrence of gastric cancer were unrelated to the prevalence of node involvement. The frequency of recurrence in EGC cases without node involvement was low (1.8%, 10 of 558). Recurrence was not, however, exceptional in those with metastatic nodes (9.5%, 6 of 63). EGC patients with lymph node metastasis, even with only a single positive node, constitute a high risk group for EGC recurrence.
Reoperative Thyroid Surgery
Authors: Chao Tzu‐Chieh , Jeng Long‐Bin , Lin Jen‐Der , Chen Miin‐Fu 
Published: August 2002

AbstractReoperative thyroid surgery is an uncommon operation associated with a high complication rate. We retrospectively reviewed the data of 115 patients to study the incidence of complications after reoperative thyroid surgery. There were 107 women and 8 men (13.4:1.0) with an average age of 42.8 years (range 18–80 years). The most frequent indication for reoperation was completion thyroidectomy for a carcinoma identified by permanent sections (50 patients, 43.5%). Reoperative surgery was performed on 13
(11.3%) patients with recurrent thyroid cancer. The remaining 52 patients underwent reoperation for recurrent thyrotoxicosis (12 patients, 10.4%), recurrent nodular goiter (28 patients, 24.3%) or recurrent multinodular goiter (12 patients, 10.4%). Seven patients with recurrent nodular goiter and one patient with recurrent thyrotoxicosis underwent total thyroidectomy for the presence of malignancies that were identified by frozen sections. Overall, the interval between the initial and reoperative procedures ranged from 1 day to 33 years (2335 ± 272 days). The length of hospital stay was 5.8 ± 0.5 days. The length of time needed for reoperative thyroid surgery was 122.0 ± 6.2 minutes. There was no 30‐day perioperative mortality. The postoperative complications consisted of transient hypoparathyroidism in six patients (5.2%), permanent hypoparathyroidism in two patients (1.7%), transient RLN palsy in 3 patients (2.6%), and permanent recurrent laryngeal nerve palsy in two patients (1.7%). Reoperative thyroid surgery can be performed safely with little morbidity to the patient.
Therapeutic Management of Rare Malignant Pancreatic Tumors in Children
Authors: Vossen Sandra , Goretzki Peter E. , Goebel Ulrich , Willnow Ulrich 
Published: August 2002

AbstractMalignant pancreatic tumors in children are rare. The major problem for the clinician is a lack of experience and of accepted therapeutic strategies. Malignant pancreatic tumors in children show a pattern different from that in adults. In infants, especially pancreatoblastomas, solid cystic tumors of females, and endocrine carcinomas of the pancreas must be expected. We report our experience in three patients with malignant pancreatic tumors (one pancreatoblastoma and two malignant endocrine pancreatic carcinomas) and review the present literature with a focus on the typical clinical and biologic features and the presently recommended therapeutic strategies. Pancreatoblastomas and solid cystic tumors are mainly found in the head of the pancreas. Fibrotic capsules with rare, late metastases are characteristic of these tumors, indicating total resection to be an important therapeutic procedure. Pancreatoblastomas should additionally be treated with chemotherapy (ADM, IFO, cis‐PL, VP16). Endocrine carcinomas of the pancreas (malignant gastrinomas and malignant insulinomas) should also primarily be treated with radical surgery, including extensive lymph node dissection. In case of distant metastasis, local resection (liver) or somatostatin in combination with chemotherapy (streptozocin in the case of malignant insulinomas) may be used.
Anesthesia for Morbidly Obese Patients
Authors: Domínguez‐Cherit Guillermo , Gonzalez Raúl , Borunda Delia , Pedroza Jorge , Gonzalez‐Barranco Jorge , Herrera Miguel F. 
Published: August 2002

AbstractBariatric surgery is the most effective method for treating patients with morbid obesity, and participation of the anesthesiologist in the treatment of these patients is more and more frequent. Therefore it is important for anesthesiologists to be familiar with anatomic and physiologic implications and the pharmacologic changes associated with obesity, so they can offer optimal perioperative treatment. The present study describes a series of 37 patients with an average body mass index of 50.3 kg/m2 who underwent bariatric surgery in a third‐level teaching hospital in Mexico City. Preoperative assessment, airway management, perioperative treatment, and the incidence of complications are analyzed. We found a high frequency of associated diseases, among which diabetes mellitus and systemic arterial hypertension were the most prominent. Cardiorespiratory complications such as obstructive sleep apnea syndrome and obesity‐hypoventilation syndrome were particularly frequent (16.2% and 22.0%, respectively). Both general anesthesia and mixed anesthesia (peridural block plus light general anesthesia) were employed. The incidence of complications related to perioperative and anesthetic management was low. We discuss and propose protocols for the evaluation and management of airway and associated cardiorespiratory complications.
Effect of Protease Inhibitor on Ischemia‐reperfusion Injury to Rat Liver
Authors: Jung Sung‐Eun , Yun Ik‐Jin , Youn Yeo‐Kyu , Lee Joong‐Eui , Ha Jongwon , Noh Dong‐Young , Kim Sang‐Joon , Oh Seung Keun , Choe Kuk‐Jin 
Published: August 2002

Abstract.Liver failure due to ischemia‐reperfusion injury, believed to be closely related to the generation of oxygen‐free radicals, is a serious problem during liver surgery. Gabexate mesilate, a synthetic protease inhibitor, suppresses the extracellular release of oxygen‐free radicals in the microvascular endothelium. To determine its effects on ischemia‐reperfusion injury to the liver, we performed experiments with rats. We divided the animals into two ischemia‐reperfusion groups: an experimental group, which underwent ischemic injury for 30 minutes, along with the infusion of gabexate mesilate, and a control group, which underwent injury only. Each group was then divided into four subgroups: ischemic injury only and 60‐, 120‐, and 180‐minute reperfusion injury. The test parameters were tumor necrosis factor α (TNFα) and interleukin‐6 (IL‐6) in serum and superoxide dismutase (SOD), catalase, and malondialdehyde (MDA) in liver and lung tissues. The experimental group had a significantly higher liver SOD and catalase levels and a significantly lower level of liver and lung MDA than the control groups. TNFα levels in the experimental groups were significantly lower during the early phase, but a comparison of IL‐6 levels between the two groups yielded no differences. Levels of lung catalase and SOD were not significantly different between the two groups. We concluded that protease inhibitor suppressed liver ischemia‐reperfusion injury, and that it was due to an increase of antioxidant or suppression of oxygen‐free radicals. The roles of TNFα and IL‐6 in liver reperfusion injury were not clear, though TNFα might have had an effect during the early phase. With liver ischemia‐reperfusion injury, the mechanism of lung involvement might be different from that of liver involvement.
Historical Evolution of Limb Amputation
Authors: Sachs Michael , Bojunga Jörg , Encke Albrecht 
Published: August 2002

Abstract.The amputation of a limb is one of the oldest surgical procedures. In the course of medical history operative techniques and surgical instruments have been improved continuously. As early as the first century Celsus described an amputation. A major step in the development of the operative technique was the introduction of an artery forceps by Paré during the sixteenth century. Nevertheless, due to a lack of analgesics and narcotics the operation had to take only a few minutes. Therefore the amputation was completed in one cut (i.e., detachment of the skin, muscles, and bone at the same level). This technique, known as “classic circular cut,” was modified several times in the following period: to reduce suture tension Petit recommended that we transect the skin first and the muscles and bone more proximally (“two‐stage circular cut,” 1718), and Bromfield approved that the skin be cut first, the muscles more proximally and the bone most proximal (“three‐stage circular cut,” 1773). Lowdham (1679), Verduyn (1696), and Langenbeck (1810) changed the operative technique in that they used a soft‐tissue flap to cover the bone without tension (“flap amputation”).
Density‐dependent growth and reproduction of the apple snail, Pomacea canaliculata: a density manipulation experiment in a paddy field
Authors: Tanaka K. , Watanabe T. , Higuchi H. , Miyamoto K. , Yusa Y. , Kiyonaga T. , Kiyota H. , Suzuki Y. , Wada T. 
Published: August 2002

AbstractTo examine density dependence in the survival, growth, and reproduction of Pomacea canaliculata, we conducted an experiment in which snail densities were manipulated in a paddy field. We released paint‐marked snails of 15–20 mm shell height into 12 enclosures (pens) of 16 m2 at one of five densities – 8, 16, 32, 64, or 128 snails per pen. The survival rate of released snails was 95% and was independent of snail density. The snail density had a significant effect on the growth and egg production of individual snails. This density dependence may have been caused by reduced food availability. The females at high density deposited fewer and smaller egg masses than those at low density, and consequently produced fewer eggs. The females at densities 8 and 16 deposited more than 3000 eggs per female, while the females at density 128 oviposited only 414 eggs. The total egg production per pen was, however, higher at higher snail density. The survival rates of juvenile snails were 21%–37% and were independent of adult density. The juvenile density was positively correlated with the total egg production per pen and hence was higher at higher adult density. However, the density of juveniles larger than 5 mm in shell height, i.e., juveniles that can survive an overwintering period, was not significantly different among density treatments. These results suggest that snail density after the overwintering period is independent of the density in the previous year. Thus, density dependence in growth and reproduction might regulate the population of P. canaliculata in paddies.