| 1. |
- Jansson, Patrik, 1972, et al.
(författare)
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Functional Pearl: Polytypic Unification
- 1998
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Ingår i: Journal of Functional Programming. - 1469-7653 .- 0956-7968. ; 8:5, s. 527-536
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Tidskriftsartikel (refereegranskat)abstract
- Unification, or two-way pattern matching, is the process of solving an equation involving two first-order terms with variables. Unification is used in type inference in many programming languages and in the execution of logic programs. This means that unification algorithms have to be written over and over again for different term types. Many other functions also make sense for a large class of datatypes; examples are pretty printers, equality checks, maps etc. They can be defined by induction on the structure of user-defined datatypes. Implementations of these functions for different datatypes are closely related to the structure of the datatypes. We call such functions polytypic. This paper describes a unification algorithm parametrised on the type of the terms, and shows how to use polytypism to obtain a unification algorithm that works for all regular term types.
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| 2. |
- Jansson, Patrik, 1972, et al.
(författare)
-
PolyLib - a polytypic function library
- 1998
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Ingår i: Workshop on Generic Programming.
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Konferensbidrag (refereegranskat)abstract
- A polytypic program is a program that behaves uniformly over a large class of datatypes. For functional polytypic programming this uniformity is achieved by parameterizing functions over type constructors to obtain polytypic functions. A polytypic function is defined either by induction on the structure of regular type constructors or in terms of other polytypic functions. PolyP is an extension of the functional programming language Haskell with a construct for defining polytypic functions. PolyP is a type guided preprocessor that generates instances of polytypic functions and inserts applications of these instances where needed.During the last few years we have used PolyP to construct a number of polytypic programs, for example for unification, parsing, rewriting, pattern matching, etc. These polytypic programs use several basic polytypic functions, such as the relatively well-known cata and map, but also less well-known functions such as propagate and thread. We have collected these basic polytypic functions in the library of PolyP: PolyLib. This paper describes the polytypic functions in PolyLib, motivates their presence in the library, and gives a rationale for their design. Thus we hope to share our experience with other researchers in the field. We will assume the reader has some familiarity with the field of polytypic programming.Of course, a library is an important part of a programming language. Languages like Java, Delphi, Perl and Haskell are popular partly because of their useful and extensive libraries. For a polytypic programming language it is even more important to have a clear and well-designed library: writing polytypic programs is difficult, and we do not expect many programmers to write polytypic programs. On the other hand, many programmers use polytypic programs such as parser generators, equality functions, etc.This is a first attempt to describe the library of PolyP; we expect that both the form and content of this description will change over time. One of the goals of this paper is to obtain feedback on the library design from other researchers working within the field. At the moment the library only contains the basic polytypic functions. In the future we will develop special purpose sublibraries for polytypic functions with more advanced functionality, for example for parsing and the other programs mentioned above.
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| 3. |
- Jansson, Patrik, 1972, et al.
(författare)
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PolyP - a polytypic programming language extension
- 1997
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Ingår i: Principles of Programming Languages. - 0897918533 ; POPL97, s. 470-482
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Konferensbidrag (refereegranskat)abstract
- Many functions have to be written over and over again for different datatypes, either because datatypes change during the development of programs, or because functions with similar functionality are needed on different datatypes. Examples of such functions are pretty printers, debuggers, equality functions, unifiers, pattern matchers, rewriting functions, etc. Such functions are called polytypic functions. A polytypic function is a function that is defined by induction on the structure of user-defined datatypes. This paper extends a functional language (a subset of Haskell) with a construct for writing polytypic functions. The extended language type checks definitions of polytypic functions, and infers the types of all other expressions using an extension of Jones' theories of qualified types and higher-order polymorphism. The semantics of the programs in the extended language is obtained by adding type arguments to functions in a dictionary passing style. Programs in the extended language are translated to Haskell.
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| 4. |
- Jansson, Patrik, 1972, et al.
(författare)
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Polytypic Compact Printing and Parsing
- 1999
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Ingår i: European Symposium on Programming. ; 1576, s. 273-287
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Konferensbidrag (refereegranskat)abstract
- A generic compact printer and a corresponding parser are constructed. These programs transform values of any regular datatype to and from a bit stream. The algorithms are constructed along with a proof that printing followed by parsing is the identity. Since the binary representation is very compact, the printer can be used for compressing data - possibly supplemented with some standard algorithm for compressing bit streams. The compact printer and the parser are described in the polytypic Haskell extension PolyP.
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| 5. |
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| 6. |
- Svensson, Johan, 1964, et al.
(författare)
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Treatment of obese subjects with the oral growth hormone secretagogue MK-677 affects serum concentrations of several lipoproteins, but not lipoprotein(a).
- 1999
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Ingår i: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 84:6, s. 2028-33
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Tidskriftsartikel (refereegranskat)abstract
- Obesity is associated with blunted GH secretion and an unfavorable lipoprotein pattern. The objective of this study was to investigate the effects of treatment with the oral GH secretagogue MK-677 on lipoproteins in otherwise healthy obese males. The study was randomized, double blind, and parallel. Twenty-four obese males, aged 18-50 yr, with body mass index greater than 30 kg/m2 and waist/hip ratio above 0.95 were treated with 25 mg MK-677 (n = 12) or placebo (n = 12) daily for 8 weeks. MK-677 treatment did not significantly change serum lipoprotein(a) [Lp(a)] levels. Serum apolipoprotein A-I and E (apoA-I and apoE) were increased at 2 weeks (P < 0.001 and P < 0.01 vs. placebo, respectively), but were not changed at study end. Serum total cholesterol and low density lipoprotein (LDL) cholesterol (LDL-C) levels were not significantly changed by MK-677 treatment. Serum high density lipoprotein (HDL) cholesterol (HDL-C) was increased at 2 weeks of MK-677 treatment (P < 0.01 vs. placebo), but not at 8 weeks. The LDL-C/HDL-C ratio was reduced after 8 weeks of MK-677 treatment (P < 0.05 vs. placebo). Mean LDL particle diameter was decreased at 2 weeks (P < 0.05 vs. placebo), but was unchanged compared with baseline values at 8 weeks (P = NS vs. placebo). The level of serum triglycerides was increased at 2 (P < 0.05 vs. placebo), but not at 8, weeks. Lipoprotein lipase activity in abdominal and gluteal sc adipose tissue was not affected by active treatment. In conclusion, treatment with the oral GH secretagogue MK-677 affected circulating lipoproteins. The effects on serum apoA-1, apoE, triglycerides, and mean LDL particle diameter were transient. At study end, the LDL-C/HDL-C ratio was decreased. MK-677 treatment did not significantly affect serum Lp(a) concentrations at the present dose and administration protocol.
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| 7. |
- Svensson, Johan, 1964, et al.
(författare)
-
Treatment with the oral growth hormone secretagogue MK-677 increases markers of bone formation and bone resorption in obese young males.
- 1998
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Ingår i: Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. - 0884-0431. ; 13:7, s. 1158-66
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Tidskriftsartikel (refereegranskat)abstract
- The effect of 2 months of treatment with the oral growth hormone (GH) secretagogue MK-677 on markers of bone metabolism was determined in healthy obese male subjects. This was a randomized, double-blind, parallel, placebo-controlled study. Twenty-four healthy obese males, 19-49 years of age, with body mass index > 30 kg/m2 were treated with MK-677 (25 mg/day; n = 12) or placebo (n = 12) for 8 weeks. MK-677 increased markers of bone formation; a 23% increase in the carboxy-terminal propeptide of type I procollagen levels and a 28% increase in procollagen III peptide levels were seen with as little as 2 weeks of MK-677 treatment (p < 0.01 and p = 0.001 vs. placebo, respectively) while a 15% increase in serum levels of osteocalcin was not detected until 8 weeks of treatment (p < 0.01 vs. placebo). Markers of bone resorption were induced within 2 weeks of treatment with MK-677; serum levels of the carboxy-terminal cross-linked telopeptide of type I collagen were increased 26% at 8 weeks (p = 0.001 vs. placebo), and urine hydroxyproline/creatinine and calcium/creatinine ratios at 8 weeks were increased by 23% (p < 0.05 vs. placebo) and 46% (p < 0.05 vs placebo), respectively, MK-677 increased serum insulin-like growth factor binding protein-5 (IGFBP-5) by 43-44% after 2-8 weeks of treatment (p < 0.01 vs. placebo). Serum IGFBP-4 was increased by 25% after 2 weeks of treatment (p < 0.001 vs. placebo) but no significant change from baseline was observed after 8 weeks of treatment. Plasma interleukin-6 was not significantly changed by active treatment. In conclusion, short-term treatment of healthy obese male volunteers with the GH secretagogue MK-677 increases markers of both bone resorption and formation. Large increases in serum levels of IGF-1 and IGFBP-5 and a transient increase in serum IGFBP-4 were found. Future long-term studies are needed to investigate if prolonged treatment with MK-677 increases bone mass.
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| 8. |
- Tisell, L E, et al.
(författare)
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Improved survival of patients with papillary thyroid cancer after surgical microdissection.
- 1996
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Ingår i: World journal of surgery. - 0364-2313. ; 20:7, s. 854-9
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Tidskriftsartikel (refereegranskat)abstract
- A total of 195 patients had surgery for papillary thyroid cancer. The mean age at operation was 50 years. A microdissection technique was used for total thyroidectomy and lymph node clearance. Postoperative radioiodine tests showed no uptake or an uptake close to the background activity in 77% of the examined patients. By counting the lymph nodes removed at surgery we were able to check on the quality of the lymph node dissection. Men had a higher incidence (70%) of lymph node metastases than women (45%). Only 4% of the patients had radioiodine ablation of the thyroid remnant. The median follow-up time was 13 years. None of the patients below 45 years of age at surgery died of thyroid cancer. In the older age group eight patients died of thyroid cancer at a mean age of 75 years. Five of those who died of a thyroid carcinoma had distant metastases at diagnosis. Among patients with resectable disease, three (1.6%) died of thyroid cancer, all of whom had lived for more than 17 years after surgery. Hence longer follow-up is needed before we know the final mortality in our series. The results suggest that surgical technique and strategy can positively influence the survival of patients with papillary thyroid cancer.
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| 9. |
- Wikner, Johan, 1961-, et al.
(författare)
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Differences in consumption of allochthonous DOC under limnic and estuarine conditions in a watershed
- 1999
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Ingår i: Aquatic Microbial Ecology. - Oldendorf : Inter-Research. - 0948-3055 .- 1616-1564. ; 17:3, s. 289-299
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Tidskriftsartikel (refereegranskat)abstract
- A temporal study of the bacterial utilisation of allochthonous dissolved organic carbon (DOC) was performed in a lake and estuary situated in the same boreal watershed. A greater utilisation of allochthonous DOC was observed under estuarine as compared to Limnic conditions. However, the bacterial biomass yield was not significantly different between the environments, indicating a lower growth efficiency on allochthonous DOC by the estuarine bacterioplankton. The largest fraction of the allochthonous DOC utilised (20 %) was observed under estuarine conditions and coincided with the spring flood. The utilisation of allochthonous DOC and bacterial biomass yield in the experimental bottles was Limited by the availability of nitrogen or phosphorus in both environments. Our results showed that the major bacterial transformation of DOC occurred in the estuarine rather than the Limnic environment, due to the shift in physicochemical milieu and bacterial assemblage. However, the estuarine bacteria also respired a greater fraction of the DOC utilised than their limnic counterparts.
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